'Splain Me This

I've never been much for hockey.  At best, a casual observer.  But the godess & I were at the kitchen table, watching the news.  The sports segment came on & they were showing an NHL playoff game.  Let me describe.

Between one of the nets & the back wall, 4 or 5 players from both teams were holding a social in a rather physical manner, as hockey players are known to do from time to time.  Sociable types, I guess.  While this is going on, the goalie was standing on the opposite side of the goal where he usually is.  Standing there!  Watching & nothing else.  A player from the opposing team decides to give him the hockey version of a Welcome Wagon, or maybe a Tupper Ware party, rears up  & takes a full swing with his stick across the upper chest/throat area, thereby dropping said goalie.

I don't know if he got a penalty, but I need one of you who knows more @ hockey than I, to 'splain to me, why, in most circumstances like this that I've seen, the local constabulary is not called in to cuff the offending miscreant off to the hoosegow on charges of aggravated battery/aggravated battery with a deadly weapon or some such thing?  I assume that hockey, like any other sport, has something that approaches official rules, although, most of the time, you couldn't tell.  Do these people somehow assume that game rules supercede the law?

So, sports fans, I'm looking to you for help.  HELP!

RichK