For the first part, yes, I definitely could see it happening. Big deal, a fan yells at a coach. It happens all the time.
For the second part, I have to ask, what is really at issue in this thread, a fan yelling at a coach, or a player bullying an opposing fan? I don't care which team it is and which team you are a fan of, this is unacceptable behavior. If anybody here is defending Radke, then you need to take off your green-tinted glasses.