I was training someone a few years back and some Vince Basile like dumbass at the gym tried to correct me in from of my client (Basic nonsense about stretching with toning bands) After I was finished, I went back and chewed him out for all it was worth including telling him that he was old to be wearing Abrocrombie & Fitch clothes and that if he ever interfered with my job then he'll get some free dental work.Regardless as to whether a personal trainer is a complete dumbbass or not, its best to mind your own damn business.