OK, I'm obviously playing devils advocate here, and going out on a limb, but, we only have the details revealed so far, which may be right or wrong at this point, but are; big hockey player out of nowhere manhandles girl and picks her into the air, girl slaps hockey player for manhandling her and lifting her into air, hockey player hauls off and hits here.
She is at fault so far, according to the details we have, according to you.
(again, just playing devils advocate)
So if you were to be walking down a dark street at night, and I, a large man, jumped out of nowhere and tackled you, for who knows what reason, and you slapped me, I would be in the right in I threw a punch to your face (which, being my size vs yours, would likely shatter several of your facial bones) and I would be totally in the right since a "lift" or "tackle" is not really a hit, only a slap or punch can be considered as a first hit, and I was just reacting to you assaulting me after I innocently tackled you..
(again, obviously going the extreme route and just playing devils advocate, but this is what it sounds like you are saying)
I see what you're saying, but if you come out of nowhere as I was walking down a dark street and tackled me, I would not slap you, I'd go whole hog fighting as though my life depended on it.
In a club, there's a bit more protection (or at least one perceives it that way). There are other people and staff around to stop things from getting too far out of hand.
However, to go along with what you're saying... if you tackled me in a dark alley, I would go into full freaked-out rip your balls off mode, and I would expect you to hit me back. It would not be right of you to do so, but I would expect you to defend yourself once you found yourself in the situation. In fact, the fact that you were committed a wrong act in the first place would lead me to expect that you would continue to act violently.
In other words, I'd expect someone to hit me back in any circumstances, but I'd really, really, really see it coming from someone who had already jumped me unawares.
If we were in a club and you lifted me into the air, you would be out 6-8 weeks recovering from a hernia.

Seriously, I have been lifted against my will. I have back problems, so it is not pleasant, but I have never hit the person who lifted me. I have just explained that I have a bad back and being lifted hurts. Usually I get an apology; otherwise they get an invitation to do something to themselves which requires more dexterity than is possessed by most of our species.
If I hit someone, yes, I expect that they will hit me back, even if they deserved to be hit. Expecting something doesn't always mean that it's the right thing to do, but in this case, I wouldn't blame him.
In this case, I think she over-reacted. I may be wrong as I'm just thinking of this as a guy lifting a girl up in fun and flirting. If it turns out that they were moshing and he put her down in a full WWE body slam, I retract my statements.
My money on the board pledge:
$1 for each goal scored by a player after whom I have named a hamster.
An additional $5 for each hat trick scored by a player after whom I have named a hamster.
An additional $10 if any of the above goals is the GWG goal that gives us the series win.
An additional $50 if it is the GWG that wins us the Cup.
$5 for a SO by Jimmy.
Hamsters' names (current players in RED): Henrik Pavel Tomas Nicklas Dominik
Niklas Matthieu Daniel Robert
Johan Andreas Valtteri Jonathan
Andrew Patrick Ian Todd
And introducing: Jordin Damien Gustav James
TOTAL SO FAR: $27