That said....I don't know how many here have played a competitive sport at the scholarship level, but for those who have they aren't going to see this as a deal breaker. Keep in mind these kids and their success or lack there of determines if coaches continue getting a pay check. It's a tense and heated environment. Players occassionally fight, and suprising to some, coaches and players go at it occassionally - generally this is limited to verbal assaults back and forth, but I've seen and heard much worse than a shove and suck my ****. Again, in no way am I condoning or saying this isn't a concern. Just that it happens and doesn't tell me much without more info.
Were his actions directed towards a senior staff member, or a young 1st year assistant who also picks up the dirty laundry after practice? In my expierence, assistant coaches (especially young ones) are eager to prove themselves. This isn't always received well by players.
Within a locker room respect is not given based on title, it is earned based on two simple things - toughness and trust. That goes for players, coaches, etc. There's a clear hierarchy within a locker room and on a coaching staff. Practices can be immensely intense, both physically and mentally. If an assistant who hasn't earned the players respect says or does the wrong thing, no doubt that situation can and will get chippy real quick.