Although workforce disasters usually make the headlines, there are a number of “basic” human resource tasks that should not be discounted. One is the job candidate interview.

Theoretically, interviews should not be a problem. They’re a common occurrence, with no possible traps, right? After all, the candidate just wants the job and you are making the decision.

While you are indeed in charge, an interviewee may not only come back on you, but may have even planned to come back on you when he or she doesn’t get the job.

Before we go any further, be aware that there are three kinds of behavior: overt, inadvertent, and opportunistic. It’s the last one that matters here. Opportunistic behavior can also be called predatory in that the individual sees an opportunity to take advantage of someone and then does. An interview can be the breeding ground for this behavior.

Picture this scenario. You are interviewing someone and the candidate offers the information that he or she is a single parent with four children, all under the age of five. You did not ask anything that would warrant or require that information because, as a law-abiding manager, you know it’s illegal to ask for marital or dependency information according to the Department of Labor (DOL). But at some point in the interview, this information was offered and, worse yet, you put it in your notes.

That’s a big problem. Whether you purposefully or accidentally included it in the interview notes, and even if you didn’t use that information to decide on employment, the interviewee can accuse you of discriminatory behavior if he or she does not get the job.

In our hypothetical case, the candidate returns after not getting the job and they bring legal counsel. You swear the information had nothing to do with your employment decision. But no matter what you say, the opportunistic interviewee and their legal counsel will assert that it was important enough to be notated. You and your company have been nailed.

This sort of assertion is worth a costly settlement to avoid a nuisance suit.

There are even individuals who pull this stunt four or five times a year on inexperienced interviewers. This is opportunistic behavior in its most glaring light. Watch for it.

Be ready for the interview. Make sure you are only asking legal questions and writing down information that is directly relevant and material to the job. As an interviewer, carefully plan your interview with previously prepared questions for the candidates to answer. Consciously discredit any unavoidable chit-chat or unsolicited information. Only take notes that matter—responses to your DOL-approved questions.

Stick to that script and you will be safe.

Dr. Steve M. Cohen is Principal and Lead HR Consultant at HR Solutions: On Call, an advisory service for medical practices and other small businesses.