You're well aware of my position on fighting by now. I want to make it clear that it is not because of these types of incidents that I oppose fighting. I totally agree that this is noting more than assault. It would be disingenuous to tie this incident to the broader issue of fighting in hockey.
I also oppose fighting, so this is kind of friendly fire, but I disagree that an incident like the Flyers linebrawl and Emery/Holtby in particular aren't related to the broader culture of allowing fighting in hockey. The obvious comeback to that is that if you didn't allow fighting at all (by punishing it so severely as to effectively eradicated it from the sport), "assaults" like this one wouldn't be possible. Yes, you still get Ron Artest vs. the Pistons (and fans) once in awhile, no matter what the rules. But those are extreme, and extremely rare examples.
But the more subtle reason why I think the discussions are linked is that the actions of everyone in this thing flow directly from the idea that fighting is a chivalrous, honorable, and noble tradition of the game...
The linesman standing and watching Holtby get his head bashed in from behind isn't intervening because he's been conditioned to believe this is normal.
Emery wouldn't have had the thought of approaching Holtby except that he has illusions of being a boxer and plays in the sport where the only punishment for that is a 5-minute major in garbage time.
And unlike a baseball player, soccer player, or virtually any other athlete, Holtby only feels the obligation to try and fight Emery because fighting is still an accepted and celebrated part of the game, and you aren't really a man if you aren't up to the challenge of a fight. This is the reason Sidney Crosby was fighting in the Playoffs only months after missing a year with a concussion.