At some point, this string will get locked, I suspect. We will see two diverging views: one is that he got enough for what he did - his career is over and he is almost certain have a hard time finding a job in any field he finds appealing. The other is similar to the one I posted - and not all that different from the "Spiderman" rule: with great power comes great responsibility. They are not incompatible.
My state's laws are not like Colorado's: here, with few exceptions, "intent" is required for an assault, and this would not make it. However, one of those exceptions is our assault 3 (which is a felony):
RCW 9A.36.031: Assault in the third degree.. I am referring to subsections (d) ("With criminal negligence, causes bodily harm to another person by means of a weapon or other instrument or thing likely to produce bodily harm") and (f) ("With criminal negligence, causes bodily harm accompanied by substantial pain that extends for a period sufficient to cause considerable suffering"). I would sure as heck charge it, and ... let's say that coming down from that would require a significant amount of jail time (several months) for the misdemeanor (assault 4, reckless endangerment, or some other option not important to this discussion).
That said: the first major error was being there in the first place. I cannot see any excuse at all for being in a location at which there is dancing and alcohol, with the possible exception of ballroom dancing, and I am not sold on it. (Unless on-duty, of course - and those experiences have resulted in this viewpoint.) When I teach in our local reserve academy, one of the things I mention is exactly that - because booze and dancing far too often lead to fights. I know it is not all that common ... but too common for people in the field to risk. It makes me cranky. (Ok, it's an easy standard for me to live by. As a diabetic, I can't drink much or often, and I dance with a complete lack of grace ... but that doesn't mean I am wrong.) Edit: I also don't like people in general very much, and crowds at all. I almost never go to social events involving my office, and those are people I actually like and respect. I went to one last month, a colleagues 40th B-day party, and it was a rarity that drew comments.
I do see the point about leaving and waiting outside for the cops ... but that is again related to being in a stupid place, with stupid people. When you're 15, or maybe 20 ... I can see it. At 25 or so, with 4 years as an Army officer and now being a fed? Not just no. Hell no. Period.