A few days ago Carly Fiorina, the Republican nominee in California’s Senate race, got caught in one of the oldest media tricks around: an open microphone. While waiting for a CNN interview she got a bit too chatty, questioning why another Republican candidate would choose to appear on Sean Hannity’s program. Then, she took a swipe at her opponent’s hairstyle as “Sooooooooooooo yesterday.” Of course, she had no idea everything she said was being recorded.

The gaff has made the rounds on the Internet, and while some are describing the incident as simply a mistake by a novice candidate, she should have known better. One would hope this sort of thing would have been covered in her media training sessions (she did have media training before running for office, didn’t she?). Perhaps she had been warned about being on guard at all times, including before and after an interview, and just got careless.

We all make mistakes, but some are more costly than others. Fortunately for Ms. Fiorina, this incident is merely embarrassing. It certainly could have been worse.

Ad agencies that advise and prepare clients for media interviews should not take for granted that their clients will automatically remember to be vigilant around reporters, especially if they begin to feel comfortable in their surrounds. A safe assumption is that everything is on the record and may be used. It’s something that can’t be said too often.

Don Beehler provides public relations consulting services to small- and medium-sized advertising agencies and businesses.