Okay, so lawyer/rec hockey player with nothing better to do on a Sunday night chiming in. I'm going to focus in almost entirely on the interplay between the Criminal law and hockey (and then entirely Canadian criminal law, though a lot of the general principles apply in the US).
There's a lot of partially correct information out here, but partially incorrect. When you play hockey you are absolutely consenting to a certain level of physical contact. Consent is a defence to a charge of assault - it's right there in the definition of assault - it's the intentional application of force without the consent of the other person.
Federal laws of Canada
laws-lois.justice.gc.ca
But so what exactly are you consenting to when you play hockey? Generally speaking incidental body contact, depending on your league even intentional body checking. Almost all physical contact in hockey is easily covered by consent.
But guess what - there's not a hockey league anywhere - not pro, not amateur, not rec - that allows fighting. Even though the NHL tacitly allows it, it's still against the rules (5 for fighting). You also aren't consenting to other physical contact that is not allowed in the rules.
So here we go back to A: consent. If you get two willing fighters squaring off you can say they are consenting. But there is also B: self-defence. If you're being attacked and you punch back, you're protected by the principles of self defence, covered in section 34 of the Criminal Code.
Federal laws of Canada
lois-laws.justice.gc.ca
Now this covers a whole lot of factors that the court will consider in whether criminal responsibility should be found or not, including the level of force, the person's involvement in it, and prior history between the parties, etc.
So just a couple more factors to throw into the mix.
There is always the question of intent. No matter how horrible the result might be, if there a reasonable doubt about whether someone intended an action is always a defence.
And finally circling back to the question of consent - it should be noted that consent is NEVER a defence to the infliction of bodily harm. So you might square up for a willing fight, but then your opponent swings his stick and breaks your arm, consent does not factor into it.
Access all information related to judgment R. v. Jobidon, 1991 CanLII 77 (SCC), [1991] 2 SCR 714 on CanLII.
www.canlii.org
Finally, if you want to dig deeper into this question you can start with the old case of R v Watson (1975) 26 CCC (2d) 150. It's a fight between two 18 year old juniors. It goes through an analysis of lots of the factors mentioned above (though by now it's kind of old).
Access all information related to judgment Regina v. Watson, 1975 CanLII 1493 (ON CJ) on CanLII.
www.canlii.org
If you want to keep digging you can look into the old Steve Moore and Todd Bertuzzi incident, but there Bertuzzi entered a guilty plea to so there's little analysis about why exactly he was guilty.
So to summarize: I am deliberately not going to give an opinion whether this Vancouver realtor should be guilty of assault. That's what people pay me money to do, so I'm not going to do it for free. But absolutely the Criminal law can still apply to a hockey rink, and frankly a lot more often than some hockey players realize.
. You’re def the guy that walks into the locker room and everyone rolls their eyes and wish didn’t show up.
The part where people sign waivers and consents and have voluntarily agreed to the rules. These include getting punched in the face. High sticking tripping etc 
