There is NEVER a reason to assault ANYBODY. Early in my life a co-worker who served time after killing a man in a fight over something meaningless, told me, "Never get into a fight unless you are willing to kill. Because you might just get a "lucky punch" and finish him off."
As a former coach I had to endure many bad calls. Never did I lose control and often reminded my team, "Whomever told you life is fair, lied to you!!"
With all that said, I recently had to question the motives of my partner during a recent game. 
He called the final out of the game (I truly thought the runner was safe "by a mile") on a play that probably would've sent the game into extra innings. We'd had a long day doing numerous games. (note to assignors, my opinion; anything more than 2-games/day reduces quality) I drove home that night feeling the last out was called because my partner was tired. This cost the team involved a chance at the championship. Their coaches and their team's fans couldn't believe the call and almost lost control. I didn't discuss the call with my partner and we got to our cars and left quickly .
As a former coach, this kind of validates some of the calls my teams had to endure. I always hated playing the host team at any tourney, or being the last game of a long day. If the ump doing our game said it was going to be his 4th game that day.......I warned my team to expect that any close call on the bases, would be out and expect bad calls on 3rd strikes. Our pitchers learned to use that to their advantage.
As a former coach, parent and now as an umpire I truly know how emotionally involved everybody is after 8-9 hrs of hard competition. Most can control their emotions. No excuse for those who can't. Parent, player, coach or official.
Thanks for letting me vent.