7 Costly Discovery Mistakes Lawyers Make and How They Impact Case Outcomes
Discovery errors can derail even the strongest cases, costing lawyers time, money, and favorable outcomes. This article examines seven critical mistakes that frequently occur during the discovery process, from failing to implement proper litigation holds to overlooking discrepancies between video evidence and written reports. Legal experts share proven strategies to avoid these pitfalls and strengthen case preparation from the start.
Impose Immediate Litigation Holds
Client deleted emails after litigation started thinking they were cleaning up their inbox not destroying evidence. Opposing counsel proved we'd failed to issue proper litigation holds and the judge sanctioned us heavily including adverse inference instructions telling the jury to assume deleted emails would have proven their claims. We lost a case we should have won easily.
The outcome was devastating because our liability defense was strong but the spoliation sanctions made us look like we were hiding smoking gun evidence. Jury awarded full damages plus legal fees. Client blamed me for not explaining preservation obligations clearly enough which was fair criticism.
Prevention required issuing written litigation holds immediately when disputes emerge before anyone's sued formally. Should have suspended all document deletion policies and preserved everything potentially relevant. Also needed to audit compliance ensuring clients actually stopped destroying documents rather than assuming they'd follow instructions without verification. One conversation about preservation isn't enough when people don't understand the consequences of routine deletion during active disputes.
Retain an Actuary for Pensions
In one divorce case I handled, opposing counsel didn't understand how to properly value a state pension — and unfortunately for the opposing side, neither did the judge. They relied on the "Annuity Savings Account Balance" listed on the most recent annual statement, treating it like a 401(k) balance, instead of obtaining an actuarial present value. The result was that the pension was valued at roughly one-tenth of its true worth, costing my client's spouse hundreds of thousands of dollars in equitable distribution. I don't know if the other side will ever realize the mistake they made. The moral of the story is simple: any time a defined-benefit pension is on the table, retain a qualified actuary or pension valuator before negotiating — pension values are not intuitive and if the value looks straightforward, you are probably making an error..
Demand Multi-Year Financial Histories
The most costly discovery mistake in family law is the 'snapshot' error—relying on a 12-month window of financial statements rather than a multi-year look-back. In divorce litigation, a one-year period is rarely enough to establish a baseline for 'normal' spending versus intentional 'divorce-planning.' By failing to demand a three-to-five-year history, counsel often misses a sophisticated 'slow-bleed' dissipation of marital assets, where a spouse funnels consistent, smaller sums into third-party accounts or overpays tax projections to create a hidden refund cushion. Because these transfers appear as routine expenses within a narrow window, they are frequently overlooked, potentially leaving six figures in marital equity on the table.
Align Medical Records Before Production
One of the most costly discovery issues I've seen in personal injury litigation is when medical documentation is not fully organized or aligned with the theory of the case before production. Because medical records and bills are central to proving causation and damages, even small inconsistencies can give opposing counsel room to challenge credibility or minimize the value of a claim. The impact is often felt in negotiations, where leverage depends heavily on how clearly the injuries and treatment are documented.
What could be done differently is disciplined coordination early in the case. Discovery should not be treated as an administrative deadline. It requires thorough review of records, alignment between the attorney and support teams, and ensuring that production reflects a coherent narrative. In my experience, discovery is where negotiating strength is either reinforced or quietly weakened long before trial.
Assert Attorney Liens Early
As a partner at Visionary Law Group handling complex workers' comp cases and co-founder of CompFox with full access to California WCAB decisions, I've seen discovery lapses firsthand.
The costliest was a prior attorney neglecting to assert and document their lien early, as in Prudencio Martinez vs. Tetra Tech (ADJ7282108). Brent Thompson provided services but got sidelined post-change of counsel; discovery responses and settlement talks bypassed his involvement, leading to a $110k Compromise & Release approving only $16k for new counsel.
His petition for reconsideration was denied, costing him thousands in earned fees and forcing a return to trial level per WCJ recommendation--but too late for full recovery.
It could've been avoided by filing a formal lien notice during initial discovery, monitoring interrogatories for settlement signals, and using tools like CompFox for quick precedent checks on Labor Code protections.
Understand Your Client Pre-Discovery
I filed a Chapter 7 bankruptcy for a debtor, who was member of an LLC that sold goods to retailers. She personally guaranteed factoring agreements on behalf of the LLC for funding. After filing for bankruptcy, that factoring company filed an adversary complaint alleging she fabricated $900k in invoices that the factoring company funded the LLC on, but could never collect. They hired a big-name Texas firm and sought nondischargeability of debt. What unraveled in discovery made them drop their entire complaint and walk away with zero.
During discovery, plaintiff's counsel purposely withheld witnesses, documents and communications with other LLC members and invoiced retailers. Even the operative factoring agreements were incomplete, but we had them. As discovery progressed, the money flow and communications couldn't be ignored. One entity funded the LLC but repayments were directed to affiliates. The names of other LLC members were on the fabricated invoices. They became evasive to our requests. Key records were withheld and discovery demands were avoided. At the debtor's deposition, counsel surreptitiously read out financials and hid names to illicit damaging answers. Counsel also came with two "client reps" but resisted identifying them or their employer. We got their names on record anyway, traced them, and found they simultaneously worked for affiliate factoring entities that funded and received payments on the same accounts. That led to a money trail that collapsed their narrative. They also scheduled same day, back to back depositions of the other LLC members they directly dealed with so to prevent meaningful cross examination by us. Their withholding led us to dig deep and uncover a likely laundering scheme through multiple affiliates and the other LLC members. Once that inference arose, they cancelled their depositions of the other LLC members and dropped their complaint before we could depose their employees.
Plaintiff's counsel wasn't diligent with its client and focused more on billable hours. They risked exposing their client's financial schemes. They faced motions, sanctions, and a misconduct record. So they voluntarily dropped their fraud complaint entirely. The debtor received a complete discharge of all her debt. The lesson is simple. Know your client and the record before discovery. Seek the truth, not a narrative. Games and intimidation don't create leverage. They create a record that collapses credibility, and the claim.
Compare Video to Reports
The most costly discovery mistakes I've seen haven't come from bad intentions, they have come from assumptions.
One case that has always stuck with me involved a misdemeanor charge for Failure to Identify / False Identification. On paper, it looked airtight. The complaint, the police report, and even the prosecutor's summary all stated that my client gave the name "Jazz" to the officer. Every document repeated the same allegation as if it were unquestionable fact.
But from day one, my client insisted he never gave a false name.
When multiple official documents tell the same story, there's a natural tendency to assume the narrative is accurate. Early in my career, I realized how dangerous that assumption can be. In criminal cases, someone's freedom is at stake. You cannot rely solely on what's written — you have to verify it.
So we reviewed the body camera footage.
The video told a completely different story. It showed clearly that my client never provided the false name alleged in the reports. The officer simply misheard him. The charge simply did not occur as described on paper.
The costly mistake wasn't ours. It was the failure to thoroughly review the video evidence before moving forward with the case. The written discovery had been accepted at face value, but no one had carefully compared it to the actual recording. Once we did, the discrepancy was undeniable.
The impact was significant. A person was formally charged with a crime that, based on objective evidence, did not happen. Court resources were wasted. Time was lost. And trust in the system suffered.
In criminal practice, heavy caseloads are a reality. Everyone is busy. But video evidence, especially body camera footage, is often the most important discovery in a case. It captures context, tone, and nuance that written summaries can miss or mischaracterize.
What could have been done differently is simple: a complete, methodical review of all discovery before maintaining the charge. That means watching every minute of footage and testing the written narrative against the actual evidence.
That case reinforced something I carry into every matter I handle in my Collin County criminal defense practice: paper discovery is only the starting point. Real diligence requires digging deeper.
When someone's freedom is on the line, assumptions are the most costly discovery mistake of all.
