[Whiteshepherds]

The guys I know that were on the K9 unit, including my father hold the belief that "if the dog can't trust you, why should it want to work for you?" and fully support positive reinforcement and ball rewards. Is this not typical?

Maybe not always typical but that's not the point. The trainer was making an assumption and using a stereotype to formulate an opinion. It says a lot more about his lack of knowledge than it does about anything else.

I once had trainer tell me that you could tell the temperament of a GSD by their color, (really, she actually spouted off the list) and, the longer the coat the more reactive the dog would be. sigh