[user104658]

You definitely shouldn't work security if you can't keep your cool in response to violence... I'd also even with the job out of the equation though, argue that any physical retaliation to a drink being thrown is a massive over-reaction and quite concerning. Even if it was just the shoving to the ground. Kicking in the head...? ...because you got a drink over you...? No I don't think that's a normal "pushed to the edge" reaction, I think he might want to explore some sort of anger management therapy.

I'm even trying to think of extreme scenarios. I'm not a violent person and generally wouldn't hit (or even throw stuff) for any reason but let's say an extreme scenario where I look out the window and an adult man has just hit one of my kids. Would I get aggressive and shove? Definitely. Would I if I lost my cool start throwing punches? Very possible... but... would I aim a couple of kicks at their head on the ground. No... even in that circumstance... it's really a next-level form of aggression.