In today’s litigation landscape, you need to know how digital evidence moves, lives, and dies. A single misstep in handling electronically stored information (ESI) can lead to spoliation sanctions, unfavorable rulings, or even the total collapse of a case.
Here are some common and critical eDiscovery errors attorneys make, with real-world examples of what can go wrong, and how to avoid letting an eDiscovery mistake tank your case.
The clock starts ticking the moment litigation is reasonably anticipated, not when the complaint is filed. Failing to issue a legal hold quickly can result in lost or overwritten data, and courts have little patience for parties that claim ignorance.
In an employment discrimination case, a company delays placing a legal hold for three weeks after receiving a demand letter. By then, key Slack messages and Zoom recordings have already been auto-deleted. The court rules the data loss is due to negligence and issues an adverse inference jury instruction. The result? A seven-figure settlement, driven not by the merits of the case, but by preventable evidence loss.
Avoid it: Create a litigation response playbook and empower someone on your team to issue holds immediately. Document everything.
Dragging and dropping files into a folder isn’t collection, it’s destruction (at least in the eyes of the court). Improperly collected data can lose critical metadata like timestamps, authorship, and access history. Worse, it opens the door for opposing counsel to challenge authenticity.
In a breach of contract case, the plaintiff’s team prints emails to PDF and hands them to the court. The defense correctly argues that the emails could be edited, lack headers, and have no forensic trail. The judge excludes the emails entirely.
Avoid it: Use forensic-grade tools and professionals when collecting ESI, especially from mobile devices, cloud platforms, or personal accounts.
Overcollection leads to bloated review sets and skyrocketing costs. Undercollection can lead to missed evidence and accusations of selective production. Both signal to the court that you’re not in control of the process.
In a trade secrets case, defense counsel overcollects 12TB of client data without filtering by custodian or timeframe. The review cost alone exceeds $400,000 and the judge refuses to grant cost-shifting due to the firm's “lack of proportionality and technical planning.”
On the flip side, we’ve seen attorneys only collect inbox emails, forgetting attachments, calendar entries, or messaging apps entirely. That kind of oversight can be exploited.
Avoid it: Work with digital forensics professionals to scope your collection accurately. Use data maps, custodian interviews, and targeted filtering.
If your discovery strategy begins and ends with email, you’re likely missing half the picture. Collaboration tools like Slack, Teams, Google Workspace, Dropbox, and Asana hold massive volumes of potentially responsive data, often in fragmented or non-obvious formats.
In one internal harassment case, the damning conversation does not happen over email; it happens in a private Slack channel. Because the legal team does not know Slack data has to be exported via API or admin panel, they miss it. The case is dismissed for failure to produce responsive records.
Avoid it: Expand your discovery scope to include chat apps, shared drives, project management tools, and mobile data.
Chain of custody isn’t just for criminal law. If there’s any chance that a piece of digital evidence will be questioned, you’ll need to prove exactly where it came from, when it was collected, and that it has not been altered.
A civil fraud case collapsed when the plaintiff’s forensic image was discovered to have been made with outdated tools and no log of who handled the drive or when. The court excluded all digital evidence derived from the image.
Avoid it: Maintain a verifiable, timestamped record of every handoff, action, and tool used during evidence collection.
If the other side brings in a qualified digital forensics expert and your only defense is, “our IT guy pulled it,” you’re already behind. Courts are increasingly deferring to experts who can explain technical evidence clearly and credibly.
In a construction dispute involving GPS tracking data, the plaintiff's expert reconstructs the timeline down to the minute. The defense fails to hire a rebuttal expert and cannot explain discrepancies. The judge calls the plaintiff's evidence "decisive."
Avoid it: Bring in your own expert early—not just to respond, but to shape the narrative and help prevent mistakes before they happen.
Most eDiscovery errors aren’t malicious, they’re preventable. But once they happen, the damage is done. The key is knowing when to handle things in-house and when to bring in professionals with deep technical and legal experience.
At Blackfish Intelligence, we’ve worked alongside attorneys in high-stakes litigation, regulatory actions, and internal investigations. We don’t just handle data. We explain it, defend it, and make it hold up in court.
If you’re facing complex discovery, worried about exposure, or need a second opinion on your current process, schedule a free consultation today.