As a software engineer, I often need to elicit information from others: Requirements, technical specs, how something failed, etc.
Sometimes it's easy. More often it is not. Even the most careful, cooperative conversation can be misleading. The fact that the Reid Technique is used by law enforcement to collect such critical information is scary.
The best confessions are the ones that reveal "guilty information" - information that is to available to people not involved in the crime.
The Science Mag story talks about tracking down a potential problem with a computer crash. I have certainly been there. It is possible for some people to accurately reproduce exactly what they have mistakenly done (assuming they ever discovered it), but it's not common. In the best of cases, the person can, through experimentation, reproduce the problem. But failing that, the best I can do is understand and capture exactly what they are saying and know that in all probability, what they are saying is basically substantive - but from the point of view of someone that was caught off guard by the situation.