Why Interview Answers Don’t Always Match What Happened

One way an investigation interview can go off track is by assuming someone is lying when their interview answers don’t match what happened. When details don’t match, we can make a quick assumption: they’re not telling the truth.

But in most cases, they are telling you what they remember. Memory doesn’t work like a recording. Research in cognitive psychology shows that memory is reconstructive. People don’t store exact copies of events. They store pieces, impressions, and meaning, and then rebuild the memory each time they recall it. That matters in investigations because when investigators expect perfect interview answers, normal memory gaps can look like deception.

What Research Tells Us

Research has consistently shown that memory is influenced by time, stress, post-event conversations, and expectation. Details fade quickly, especially sequence and timing, and high-stress situations reduce accuracy. What people hear after the event can reshape what they remember. And people tend to recall what makes sense, and what actually happened may be different from what was expected.

Psychologist Elizabeth Loftus demonstrated that even small changes in wording can alter memory. In one study, participants estimated higher speeds in a crash when the word “smashed” was used instead of “hit.” Memory is imperfect and also influenced.

During interviews, it’s common to hear statements like, “I’m pretty sure that happened first,” and “I think it was around that time.” People get confused about the colors of things, what was said exactly, or the location of equipment or objects.

Those aren’t signs of dishonesty. It’s just how memory works.

What It Can Look Like

In one investigation, a piece of equipment failed during a routine operation. Two operators were interviewed separately. Both were experienced, both were confident, and both were certain they remembered the sequence correctly. But their timelines didn’t match. One operator said a valve was opened before the alarm activated. The other said the alarm came first. The difference mattered because it changed how the team understood the event.

At first, the inconsistency raised concern. Was someone withholding information? Was someone trying to protect themselves? As the investigation continued, additional evidence was collected, including control system data, alarm logs, and equipment status.

The timeline became clear. The alarm had activated first. Neither operator was lying. Both had reconstructed the sequence in a way that made sense given their roles and expectations. Without the data, the investigation could have turned into a debate about credibility. With the data, it became clear what actually occurred.

Interviews Are Just One Source of Information

When memory is treated as fact, investigations start to drift. Investigators begin to rely heavily on interviews, resolve conflicts by choosing the most confident version, and interpret inconsistencies as credibility problems. That shifts the investigation away from evidence and toward judgment. Strong investigations treat interviews as one source of information, not the answer.

Instead of asking, “Who is right?” ask, “What evidence supports what actually happened?” That shift keeps the focus on physical evidence, system conditions, and documented facts. It allows interviews to do what they do best: highlight gaps, point to missing evidence, and reveal how the work was understood.

When someone’s story changes, it doesn’t automatically mean they are being dishonest. It often means they are reconstructing the event, filling in gaps, and trying to make sense of what happened. This is a signal to collect more evidence. Good investigators don’t rely on memory. They use it as a starting point. Because the goal isn’t to determine who gave the best “right” interview answers. It’s to understand what actually happened.

Learn More

If your investigation depends on memory alone, you are accepting a level of uncertainty you may not realize. Are you collecting the most confident story instead of the evidence? Learn about collecting better information and improving your interview skills in our 5-Day TapRooT® Advanced Root Cause Analysis Team Leader Training.