▪︎ Avoiding Impeachment – Deposition and Trial Tips for Nurses and Expert Witnesses

Impeachment is the legal process of attacking a witness’s credibility by exposing contradictions or mistakes. In practice, opposing counsel will scrutinize your earlier statements (in reports, depositions or prior cases) to find any inconsistency with your trial testimony. In other words, if you testify one way at a deposition or in a report or in the medical record and another way at trial, counsel can use the earlier statement to impeach you. Consistency is critical: the better aligned your testimony is with your prior statements, the less opportunity opposing counsel will have to undermine your credibility.

An expert witness can even be impeached with sworn testimony given in a prior unrelated case if it contradicts their current testimony. Most rules of evidence – e.g. Federal Rule 613 – explicitly allow impeachment by prior inconsistent statements. As one court put it, “prior inconsistent statements in the same or similar cases are a “testimonial hazard”. Understanding this hazard is the first step to avoiding it.

Common Reasons for Inconsistencies

• Speculation or Guessing: A frequent problem is answering a question without full knowledge. In everyday nursing, you’re trained to have answers, but in depositions even small guesses “can prove catastrophic” if they turn out to be wrong.
• Volunteering Unasked Details: It’s natural to want to give a full answer, but offering extra information without being asked can open you up to new lines of attack. Depositions often see experts “providing full and complete answers with plenty of detail,” thinking it show they have expertise on the topic. In reality, volunteering unsolicited information simply gives opposing counsel more ammunition. Keep answers tight and only respond to the specific question asked.
• Opinions Beyond Expertise: Nurses form opinions daily, but in court, your expert opinions must stay within your training and the evidence. If you stray outside your area (for example, commenting on physicians’ decisions when that’s beyond your role), you risk inconsistency.
• Memory Lapses Over Time: If you testify weeks or months apart (e.g. deposition vs. trial) without reviewing transcripts or notes, you may accidentally misremember a fact. Minor things like times, dosages, or chart entries can be hard to remember exactly. If your trial testimony conflicts with earlier statements (i.e. given in deposition), opposing counsel will pounce. Always check your records beforehand to refresh your memory and avoid such inadvertent inconsistencies.

Best Practices for Consistency

• Thorough Preparation: Do your “homework” early. Review all relevant records, reports, and deposition transcripts before any testimony. Work closely with your attorney to identify any possible discrepancies in advance. If past statements or reports differ, clarify them now so no surprises arise later.
• Review Prior Testimony: Before trial, read your own deposition and any affidavits. Make notes of anything you said differently and discuss them with counsel. If you spot an error, fix it before trial (for example, an errata sheet for the deposition). As advised in expert training, “correct errors as soon as they are discovered,” so you’re not blindsided by impeachment later.
• Active Listening and Thoughtful Answers: Always pause and ensure you understand a question before answering. Make sure you understand the question and take a moment to formulate your response. As one guide notes, slowing down “will help the expert appear to deliberate” and avoid off-the-cuff mistakes.  It’s better to ask for clarification than to rush into a wrong answer.
• Answer Precisely – Don’t Volunteer: Stick to answering only what is asked. Don’t offer any more information than you were asked about. If a question can’t be answered with a simple “yes” or “no,” it’s acceptable to say so or explain carefully, rather than guessing or rambling.
• Maintain Professional Demeanor: Answer calmly and confidently. Avoid appearing defensive when an attorney objects or when you’re challenged. Remember that opposing counsel’s job is to probe for weakness. Keep your tone respectful. Avoid any mannerisms of nervousness (e.g., fidgeting) as these can signal uncertainty.
• Communicate with Your Attorney: You can ask to take a break and you can ask your attorney questions.

Real Med Mal Case Example

In this case the patient had his neck adjusted by a chiropractor, and immediately developed (or severely worsened) a vertebral artery dissection that developed into a massive posterior circulation stroke. Due to a series of miscommunications and errors by the radiologist, neurologist, ER doctor, and ICU PA, the diagnosis was missed. The patient was left with permanent locked-in syndrome.

The ER doctor went back and changed the medical records to try to make himself look better and shift fault to the neurologist. The ER doctor’s defense expert witness claimed that it was fine for the defendant MD to go back change the medical record the next day, at which point the plaintiff’s attorney played a clip of him on a podcast saying the exact opposite:

Key Takeaways:

Any notes made after an incident may be suspect, but especially anything added on a subsequent day. Anything you have previously said on social media, in expert advertising and websites, articles you’ve written, etc. can be used to impeach you if they are inconsistent with what  you are testifying to in a case.

As a nurse expert witness, treat every statement you make – in reports, depositions, and trial – as part of one continuous record. Before testifying, review everything you said previously. Never hesitate to pause or ask for a moment to think about a question. If you’re unsure, it’s far better to say, “I’m not certain; I’ll need to check my notes,” than to guess.

Remember, under the evidence rules you will be given a chance to explain any alleged inconsistency, but it’s far preferable that you preempt such conflicts. With clear, truthful, and consistent testimony, you uphold your role as a reliable expert and avoid the “testimonial hazard” of impeachment.

By preparing thoroughly, listening carefully, answering precisely, and correcting any errors immediately, you can greatly reduce the risk of impeachment!

If you would like personal coaching to help you prepare for deposition or act as an expert witness, I am available for mentoring. I have prepared many witnesses, both lay and expert, for deposition and trial, and would be happy to help you prepare. 

To learn more about these legal topics, check out our courses on demand (with extensive written materials):

➡️ 1-Day Expert Witness Training Program (7.2 CE Hours)

Sincerely,
Laurie Elston JD BSN
www.NursingLawCenter.com
Law Office of Laurie R. Elston Inc.
📞 T: (805) 481-1001
📧 Email: [email protected]