Due diligence document production in an M&A deal moves fast, and volume works against careful review. Thousands of files often get sorted into shared folders on a tight deadline, making it easy for a privileged memo or legal advice email to end up in a batch headed for the counterparty. 

Depending on the jurisdiction and the precautions taken, that kind of mistake can put a privilege waiver on the table, not just an awkward disclosure. Yet privilege review is often treated as a byproduct of general document organization rather than a distinct legal judgment call. 

This article lays out a deliberate process for protecting privilege during review: what to flag, how to log it, how clawback agreements reduce exposure, and what to look for in a data room built for privilege-sensitive productions.

Why Privilege Protection Requires Its Own Review Step

The pace of due diligence document production is the root of the problem. When teams sort through thousands of files under a tight deadline, privileged material can get swept into a general collection folder or shared with a counterparty before anyone catches it.

Whether that mistake amounts to a waiver depends on the jurisdiction and on whether the producing party took reasonable steps to prevent and correct the disclosure. Under Federal Rule of Evidence 502(b), disclosure does not waive privilege only if it was inadvertent, reasonable steps were taken to prevent it, and the holder acted promptly to fix the error once discovered, as a recent law firm client alert on Rule 502(d) orders explains. That three-part test rewards firms that built a review process in advance.

Deciding what counts as privileged is also not a task you can hand to whoever is organizing the data room. It calls for a legal judgment about the purpose of a communication and who was a party to it, which is why attorney-client privilege due diligence needs its own dedicated step rather than being assumed in the general review workflow.

What Documents Typically Require Privilege Review

A few categories show up again and again in privilege review, and each deserves a second look before it goes anywhere near a shared folder:

• Attorney-client communications and legal advice memos. These get pulled into broader document sets when custodians export entire email threads or shared drives without separating out legal correspondence. 
• Work product prepared for litigation or the transaction. Memos analyzing deal risk, drafted by or for counsel, fall outside what a counterparty should see during diligence. 
• Internal legal risk analysis. Assessments of exposure, contract disputes, or regulatory issues often reside in the same repositories as ordinary business records, making them easy to miss.
  

Building a Privilege Log Before Documents Go Into the Data Room

A privilege log records what was withheld, when, and why. Building it before production begins, rather than after a dispute arises, gives you a defensible account of the review process if the withholding is ever challenged later in the deal or in litigation.

At a minimum, the log should identify each withheld document by category, date, and the basis for the privilege claim. That level of detail matters if opposing counsel later argues that a document was withheld improperly or that the privilege was waived through careless handling.

This step also requires coordination between legal counsel and whoever manages the data room so flagged documents are excluded before the room opens to the counterparty, rather than identified after the fact. If you are evaluating platforms for this kind of workflow, reviewing the best virtual data room providers for law firms is a reasonable starting point for comparing staged access, audit logging, and redaction capabilities against generic file-sharing tools.

Clawback Agreements and Rule 502 Protections

A clawback agreement, negotiated under FRE 502(d) or 502(e), provides parties with a contractual or court-ordered mechanism to recover inadvertently disclosed privileged material without treating the disclosure as a waiver. A 502(d) order carries the most weight, since it can protect against waiver in other proceedings, not just the one where it was entered, while a 502(e) agreement between the parties generally binds only those parties unless a court incorporates it into an order.

Timing matters here. A clawback agreement negotiated before document exchange begins gives both sides a clear procedure to follow if something slips through. Negotiating one only after an inadvertent disclosure has already happened puts you in a weaker position, since the other side has less incentive to agree to favorable terms once it already holds the document.

It’s worth being direct about the limits: a clawback agreement is a backstop, not a substitute for review. A recent legal analysis of privilege preservation in M&A due diligence notes that courts differ in how they apply related doctrines, such as the common interest doctrine, and that the interest shared between deal parties must be genuinely legal, not merely commercial, for that doctrine to apply. A signed clawback agreement reduces the consequences of a mistake, but review is still what prevents most mistakes in the first place.

Choosing a Data Room That Supports Privilege-Sensitive Review

Not every data room is built to the level of control that privileged document review M&A work demands. Redaction tools, granular permissioning, and staged release features matter far more here than in a typical corporate due diligence process, where the main concern is organizing financial and commercial records rather than screening for privilege.

Before committing to a platform, confirm two things:

• First, it can pull a document from view immediately if it turns out it was disclosed by mistake.  
• Second, the resulting access log is detailed enough to show exactly who viewed or downloaded the document before it was removed, since that record can support a clawback claim if the disclosure is ever challenged.
  

Common Privilege Protection Mistakes During Due Diligence

A few recurring mistakes account for most privilege problems that surface during due diligence:

Mistake	Why it creates risk
Delegating document organization to non-legal staff without a clear flagging process	Privilege calls require legal judgment that general document review does not include
Relying on keyword search alone to identify privileged material	Search terms miss context-dependent privilege calls, such as legal advice embedded in an otherwise business-focused thread
Skipping a clawback agreement before production begins	Leaves no contractual backstop if an inadvertent disclosure privilege issue arises later
Treating the data room as the review step	A data room organizes documents; it does not replace a legal privilege determination made before upload

Conclusion

Protecting privilege during due diligence document review doesn’t happen automatically, even in a well-organized data room. It takes a dedicated process: identifying the documents that need closer review, building a privilege log before production begins, and negotiating a clawback agreement while there is still time to set favorable terms. 

FRE 502 gives deal counsel real tools to limit the damage from an inadvertent disclosure, but those tools work best as a backstop to careful review, not a replacement. 

Firms that treat privilege review as a separate step, supported by a data room with appropriate access controls, are in a much better position if a disclosure dispute arises after closing.