ALLERGAN, INC., ALLERGAN PHARMACEUTICALS IRELAND, UNLIMITED COMPANY, ALLERGAN USA, INC., AND ALLERGAN SALES, LLC Plaintiffs, v. REVANCE THERAPEUTICS, INC. Defendant Civil Action No. 3:23-cv-00431 United States District Court, M.D. Tennessee, Nashville Division Filed July 25, 2025 Presnell, Todd, Special Master ORDER OF THE SPECIAL MASTER REGARDING DEREK CHAN DISCOVERY DISPUTES *1 This matter comes before the Special Master on the parties' March 21, 2025, joint statement to the Special Master (the “Joint Statement”) in which Revance Therapeutics, Inc. (“Revance”) seeks to compel Plaintiffs (“Allergan”) to more fully respond to discovery related to former Allergan and former Revance employee Derek Chan.[1] Upon consideration of the parties' briefing and submissions, as well as the exhibits submitted in support of the arguments made in the briefing, the Special Master grants in part and denies in part Revance's requested relief. I. Issues Raised by the Joint Statement[2] The Joint Statement concerns discovery disputes involving Derek Chan, a former Allergan employee who previously left the company to work for Revance, before returning to Allergan. See Joint Statement at 1. Revance raises two categories of concerns. First, Revance claims that Allergan was dilatory in informing Revance that it did not have the ability to search Mr. Chan's entire email mailbox, a delay that “caused Revance to approach ESI discovery with incorrect information.” Id. at 2. Allergan responds that it has produced a subset of Mr. Chan's custodial emails in addition to a collection of emails based on a search of Mr. Chan's email address across all individuals subject to a legal hold. Id. at 7. While Allergan does not explain why it did not inform Revance sooner about the status of Mr. Chan's mailbox, Allergan insists that Revance's insinuation that Allergan “lost” access to part of Mr. Chan's mailbox is untrue. Id. at 8. Allergan also points out that Revance does not have access to Mr. Chan's email from when he worked at Revance. See id. Second, Revance objects to Allergan's objections to several Rule 34 Requests for Production of Documents (“RFP(s)”) concerning Mr. Chan's documents largely, but not only, related to his BOX account. Raising its statute of limitations defense, Revance asserts that several categories of documents are relevant. Allergan responds that “Revance fails to justify why Allergan should reopen its ESI search terms” and expand the scope of the previously agreed-on discovery. Id. at 9. Allergan also pushes back on Revance's characterization of the extent of Allergan's previous disclosures and argues that the burden of discovery is not proportionate to the needs of the case. Id. Finally, both parties invoke the “goose/gander” proverb, arguing that the other party should produce reciprocal discovery. *2 Within these two categories of concerns, Revance requests an order that Allergan respond to the following five questions and produce documents relating to those questions: Produce all document retention policies applicable to the preservation of Mr. Chan's Allergan/AbbVie ESI/mailbox data (from 2015 – present). This should include, at a minimum, the Global Records and Personal Data Retention Policy; the Global Records Retention Policy, and Corporate Records Retention Policy. Explain the reason why Allergan no longer possesses Mr. Chan's custodial mailbox. Identify when Allergan ceased to possess/have access to Mr. Chan's custodial mailbox. Identify all “other custodians who communicated with Derek Chan” from whom Allergan says it has collected emails involving Mr. Chan. In other words, disclose the custodians' mailboxes that Allergan searched to locate his emails. Identify any other agreed-upon custodian for whom Allergan lacks custodial mailbox data. Revance also seeks an order overruling Allergan's objections to RFPs 105, 109–117, 123, 124, and 130. See Joint Statement, Appendix A. II. Discussion Federal Rule of Procedure 26 governs the scope of discovery and generally allows parties to seek discovery of relevant material that is proportional to the needs of the case. See Grae v. Corrs. Corp. of Am., 326 F.R.D. 482, 485 (M.D. Tenn. 2018) (citing Fed. R. Civ. P. 26(b)(1)). Relevance, in turn, is guided by Federal Rule of Evidence 401, which defines “ ‘relevant evidence as evidence that ‘has any tendency to make a fact more or less probable than it would be without the evidence,’ if ‘the fact is of consequence in determining the action.’ ” Id. (quoting Fed. R. Evid. 401). During this process, the trial court has broad discretion to determine the proper scope of discovery. See In re Ohio Execution Protocol Litig., 845 F.3d 231, 236 (6th Cir. 2016). A. Revance's Questions Regarding Mr. Chan's Available ESI Federal Rule of Civil Procedure 26(b)(1) also contemplates that, in appropriate circumstances, one party may seek information about another party's retention efforts. Fed. R. Civ. P. 26(b)(1) Adv. Comm. Notes (stating that discovery may include information about the “custody, condition, and location of any documents” and “detailed information about another party's information systems and other information sources,” so long as “relevant and proportional to the needs of the case”); see Ruiz-Bueno v. Scott, No. 2:12-CV-0809, 2013 WL 6055402, at *1 (S.D. Ohio Nov. 15, 2013) (“Sometimes, information about discovery is a matter which ‘may aid a party in the preparation ... of his case.’ When that is true, that information is relevant within the meaning of Rule 26(b).”). But this so-called “discovery on discovery” is not automatic and courts typically disfavor it. See, e.g., Buergofol GmbH v. Omega Liner Co., Inc., No. 4:22-CV-04112-KES, 2024 WL 4291467, at *7 (D.S.D. Sept. 25, 2024). Despite the disfavor, courts have permitted this type of discovery “where there is evidence of a specific deficiency in the production.” Culliver v. BP Exploration & Prod., Inc., No. 21-cv-4942-MCR-HTC, 2022 WL 19568966, at *2 (N.D. Fla. Nov. 29, 2022) (citations omitted); Stein v. U.S. Xpress Enters., Inc., No. 19-CV-00098-TRM-CHS, 2022 WL 511553, at *3 (E.D. Tenn. Feb. 11, 2022) (denying “discovery on discovery deposition” where the moving party had not “demonstrated any preservation lapse or productions issues that would call into question Defendants' preservation and production efforts” (cleaned up)). To secure relief, the party seeking discovery must explain in sufficient factual detail the alleged deficiency in its opponent's production or the type of evidence the opponent lost or failed to preserve. Conclusory assertions, suspicions that an opponent's production is incomplete, and speculation of wrongdoing are insufficient to warrant additional discovery. Culliver, 2022 WL 19568966, at *2. Here, Revance slightly crosses this threshold because Allergan does not have access to Mr. Chan's entire email database and therefore Revance should receive the limited discovery described below. *3 First, Revance requests all document retention policies, including some specific policies Revance requests by name. Allergan responds by noting that it has already produced document retention policies, including the Global Records and Personal Data Retention Policy which became effective in 2018. See Joint Statement at 8. Allergan has also committed to producing the specific policies Revance requested if and when Allergan locates them. Allergan is ordered to also produce the appendices or other documents listing the length of time for data retention and disposal guidelines, as well as older data retention policies from Mr. Chan's first stint of employment at Allergan. Second, Revance wants Allergan to explain why it no longer possess Mr. Chan's custodial mailbox, and when it learned that information. See Joint Statement at 3. In the Joint Statement, Allergan explains that Mr. Chan was not put on a legal hold for this case because he had left Allergan almost three years before Allergan sued, and Allergan only learned of potential issues with Mr. Chan during discovery, which is why he was not named in the Complaint. See id. at 8. These requests are thus denied as moot. Third, Revance asks Allergan to identify the custodians whose mailboxes Allergan searched to locate Mr. Chan's emails. Allergan makes the fair point that Revance can cross-reference the emails that Allergan has produced and generate its own list. See also Fed. R. Civ. P. 26(b)(2)(C)(i). However, it may be the case that Allergan searched a custodian's mailbox and did not find any emails to or from Mr. Chan, or searched a custodian's mailbox and withheld the only responsive communications for privilege. And, as Allergan acknowledges, it “is continuing to produce emails in its possession, custody, or control from Mr. Chan's custodial data subject to the parties' ESI protocol.” Joint Statement at 8. Accordingly, a cross-check may not capture the entire search. Additionally, the burden on Allergan is minimal. See Apple, Inc. v. Samsung Elecs. Co. Ltd., No. 12-CV-0630-LHK (PSG), 2013 WL 1942163, at *2 (N.D. Cal. May 9, 2013) (ordering production of custodians and search terms because there was “no evidence from which the court could find that collecting a list of search terms and custodians compiled within the last six months would be oppressive or burdensome”). Allergan is thus ordered to provide Revance a list of the mailboxes Allergan searched for Mr. Chan's emails. Fourth, Revance's fifth question asks Allergan to identify any other agreed-upon custodians for whom Allergan lacks mailbox data. Allergan responds that it is “not aware” of inaccessible custodial mailbox data for the 25 agreed-upon custodians. The Special Master accepts Allergan's representation and denies the request. Going forward, if either party learns that it no longer has full access to an agreed-upon custodian's mailbox, it is ordered to disclose that information to the other party immediately. B. Requests for Production Revance's second bucket of requests concerns several RFPs and Allergan's objections to them. The Special Master addresses each in turn. RFP 130. Revance seeks “[a]ll documents in Derek Chan's BOX account.” Both parties agree that “Revance has asserted a statute of limitations defense and is entitled to discovery on that defense,” Joint Statement at 9, but Allergan objects to the temporal scope, see Joint Statement at 9.[3] Although the parties originally agreed on a set of dates under the ESI protocol, the Special Master finds that documents in Mr. Chan's BOX account outside of those dates may be relevant to Revance's statute of limitations defense. While the Special Master is mindful of imposing additional burdens on Allergan, it appears that Allergan has already produced (and thus, reviewed) several documents from Mr. Chan's BOX account. See, e.g., Joint Statement at 9 (“Allergan has produced the documents (regardless of date) on which Allergan bases its claims with respect to Mr. Chan.”). Allergan has also already produced non-privileged documents from January 2014 to June 2016. See id. at 5 (citing Ex. H). *4 Both parties also acknowledge that at least some of the materials in Mr. Chan's BOX account like concert schedules are irrelevant to this case. Id. at 9. This means that ordering the production of the entire BOX account would definitionally include irrelevant materials. The Special Master therefore orders Allergan to produce all non-privileged documents from Mr. Chan's BOX account relevant to Revance's statute of limitations defense. To facilitate this production, the parties must confer about appropriate search terms. Because any claims would have accrued by April 28, 2020, Allergan's production should be from the time Mr. Chan returned to Allergan in June 2016 through April 28, 2020. RFP 105. Revance seeks all documents with Mr. Chan's personal email address. Allergan objects to this request as overbroad and that the request is moot because it “has already gone through that exercise by searching for Mr. Chan's Allergan email address across Allergan's platform housing emails for all individuals in legal hold.” Joint Statement at 10. But it's not clear why a search of Mr. Chan's Allergan email would satisfy a request for his personal email. The Special Master agrees with Revance that these emails are relevant—both to Revance's statute of limitations defense but also to Allergan's claims. For example, Allergan noted that “Mr. Chan testified that during his first stint of employment he emailed to his gmail account several of the documents that Allergan learned Mr. Chan used at Revance. He then also testified that he deleted those emails from his gmail account, of his own accord and volition.” Joint Statement at 10. And as mentioned above, Allergan has already searched for Mr. Chan's work email across all individuals in legal hold. Performing the same search for Mr. Chan's personal email will not be burdensome. If anything, Allergan should expect minimal results. As it noted, Allergan's first search for Mr. Chan's emails to himself yielded no emails. Allergan is ordered to search for Mr. Chan's Gmail address across the agreed-upon custodians from January 2014 to June 2016 and from the date Mr. Chan returned to Allergan in June 2016 to April 28, 2020, and produce responsive, non-privileged documents. RFPs 109–111. These are largely overlapping requests concerning the forensic imaging, collection, and retention of Mr. Chan's devices and accounts, and any investigations into Mr. Chan's access to Allergan's information. As Allergan notes, these requests are largely duplicative of RFPs 37, 39, 179, and 180, but just specific with regards to Mr. Chan. The Special Master will address those RFPs in a forthcoming Order concerning the parties' March 12, 2025, Joint Submission. Because Mr. Chan is encompassed within those RFPs as a former employee, the Special Master defers ruling on Revance's request to overrule Allergan's objections to RFPs 109–111. RFPs 112–117. These requests are for documents and communications concerning specific trade secret documents that Mr. Chan allegedly accessed during his Revance employment. Allergan made identical requests of Revance, but that is because Allergan sought discovery “on specific Allergan file names relevant to its asserted trade secrets to obtain discovery regarding Allergan trade secrets in Revance's possession.” Joint Statement at 11 (emphasis in original). This is not a goose/gander situation, as Revance argues. Revance advances two substantive arguments for these requests. First, that the documents will show how the trade secrets were developed. Second, how widely within Allergan these documents were exchanged. To the first point, as Revance notes, it has already requested trade secret development information in RFPs 16–20, and Allergan has searched and produced documents responsive to those requests. To the second point, dissemination within the company is irrelevant, as opposed to external dissemination. See Rogers Corp. v. Arlon, Inc., 855 F. Supp. 560, 572 (D. Conn. 1994) (no liability where claim “for misappropriation is essentially based upon alleged disclosure by [a company] to itself”). And Revance has propounded a separate request seeking communications about the asserted trade secrets with third parties (RFP 23) that Allergan has a production forthcoming. The Special Master denies Revance's request to overrule Allergan's objections to RFPs 112–117. *5 RFP 123. This request concerns documents concerning Mr. Chan's BOX account access from January 1, 2014 to present. Allergan identifies Roger Huff, Allergan's Associate Director of Information Security, as the custodian most likely to have responsive BOX information for Mr. Chan, and has searched for responsive documents. Yet Allergan produced responsive documents only from Mr. Chan's first stint of employment, and not his second. As explained above, the relevance of Revance's statute of limitations defense overrides the previously agreed ESI protocols. Allergan's temporal objection is overruled, and it is ordered to produce documents responsive to RFP 123 from the date Mr. Chan returned to Allergan in June 2016 to April 28, 2020. RFP 124. This request also concerns Mr. Chan's alleged retention of Allergan documents, but is not limited to his BOX account. Revance claims that Allergan has refused to certify that it has produced all documents responsive to RFP 124. Joint Statement at 6. Allergan does not address RFP 124 in its response at all. For the same reasons above regarding RFP 123, Allergan is ordered to either certify that is has produced all documents responsive to RFP 124, or to produce all documents responsive to RFP 124 from the date Mr. Chan returned to Allergan in June 2016 to April 28, 2020. III. Conclusion In accordance with the foregoing, the Special Master hereby ORDERS that: 1. The requests for relief in the March 21, 2025, Joint Statement to the Special Master regarding Derek Chan discovery disputes (attached as an exhibit to this order) are GRANTED in part and DENIED in part as follows: a. Revance's request that Allergan produce all document retention policies is GRANTED. b. Revance's requests that Allergan explain information about losing access to Mr. Chan's custodial mailbox are DENIED as moot. c. Revance's request that Allergan produce a list of custodians whose mailboxes Allergan searched to locate Mr. Chan's emails is GRANTED. d. Revance's request that Allergan produce a list of agreed-upon custodians for whom Allergan lacks custodial mailbox data is DENIED. e. Revance's request that Allergan produce documents responsive to RFP 130 is GRANTED in part and the parties SHALL meet and confer regarding appropriate search terms by August 1, 2025. The production SHALL include responsive documents from the date Mr. Chan returned to Allergan in June 2016 to April 28, 2020. f. Revance's request to overrule Allergan's objections to RFP 105 is GRANTED. The production SHALL include responsive documents from January 2014 to June 2016, and from the date Mr. Chan returned to Allergan in June 2016 to April 28, 2020. g. Revance's request to overrule Allergan's objections to RFPs 109–111 DEFERRED. h. Revance's request to overrule Allergan's objections to RFPs 112–117 is DENIED. i. Revance's request to overrule Allergan's objections to RFP 123 is GRANTED. The production SHALL include responsive documents from the date Mr. Chan returned to Allergan in June 2016 to April 28, 2020. j. Revance's request to overrule Allergan's objections to RFP 124 is GRANTED. The production SHALL include responsive documents from the date Mr. Chan returned to Allergan in June 2016 to April 28, 2020. 2. The Special Master filed the Joint Statement and accompanying exhibits under seal as a separate docket entry because the parties designated them “confidential.” Within fourteen (14) days of the entry of this Order, any party who desires for any material filed under seal in conjunction with this Order to remain under seal SHALL file a motion to seal with the Court pursuant to Local Rule 5.03. 3. Pursuant to paragraph three of the Court's Order Modifying Case Management Order and Granting Request for the Appointment of a Special Master (ECF 275), the parties have twenty-one (21) days from the date of this Order to file objections or a motion to adopt or modify any of the Special Master's rulings in this Order. *6 IT IS SO ORDERED. Signed July 18, 2025. Footnotes [1] The Joint Statement, its exhibits, and Appendix A are filed under seal as a separate docket entry because the parties designated them as highly confidential in accordance with the operative protective order. [2] Because the joint statement implicates only discrete, narrow issues, the Special Master does not provide a fulsome case background in this Order. For a description of this lawsuit's context and claims, see the “General Background” section of the Order of the Special Master Resolving Plaintiffs' Renewed Motion to Compel Production of Certain Documents (ECF 302). [3] Revance also argues that Allergan should produce all the documents in Mr. Chan's BOX account to understand the account's security measures and the extent that Mr. Chan “commingled” trade secrets with other materials. Joint Statement at 5. The Special Master finds these rationales unpersuasive.