Good for you. I had a similar instance in which I noticed the person in charge of the metal detector speaking on his/her cell phone while passengers were processing through. Not only that, but the conversation had spilled over to the person running the x-ray machine.
I went to the TSA website, reported it as a security concern and received a phone call a few days later looking for more information. Apparently they did an investigation and saw what I was referring to on the security tapes. Doubt anything became of it, though........