I believe that like any other industry you will always have someone not being professional 100% of the time. It is life, it is being human. You cannot always have your guard up all the time. I have since entering into this profession seen those that are not professional. I have even seen it happen between teacher/parent. That is the sad part. I try my best to be professional at all times but when I catch myself lowering my guard with a parent or another staff member I do try to catch myself quickly. I take mental notes during staff meetings of what occurs and remind myself that I am unfortunately always "on" no matter where in the City of Gilbert I travel to! When I am out and about I remind myself that my students and or their parents might be around or my fellow teachers.
In my past career, I dealt with the public a great deal, so it is not new to me and I find I use a lot of my knowledge from that here, and I keep myself out of the "dog house" on a consistent basis. :-) I honestly remind myself, would it make me feel ok to be treated or talked to in a that manner? That in itself helps to regulate.