Anyone wondering exactly how subjectivity and nuance can muddy the waters when it comes to head shots in hockey and how to eliminate them need look no further than the Bell Centre.
The aftermath of Pittsburgh's 4-3 overtime win over the Montreal Canadiens on Saturday was one of remarkable contrasts.
One high-profile concussion victim resolutely unrepentant about planting his elbow into the kisser of a fellow professional on Friday, another taking a more conciliatory tack after a dangerous hit that connected with an opponent's head.
The latter was Montreal's Max Pacioretty, who should expect an audience with NHL disciplinarian Brendan Shanahan for a third-period check on Pens defenceman Kristopher Letang as he shaped for a shot in the Habs' end.
It looked for all the world like a textbook blindside hit prohibited by rule 48 - Pacioretty coming in from Letang's right and laying his shoulder and upper arm into Letang's head.
There was no penalty called on the play despite Pittsburgh's protests.
As the teams prepared for overtime, Pacioretty briefly went over to apologize to Letang - who by then had returned - and after the game went one further, explaining his version of the events.
"It's a tough decision for me, it's a tough decision for him too. He's coming across the middle, unfortunately his head is down, I feel terrible about what happened. I didn't see the replays, so I don't know what the league will think of it. But if I let him take that shot it could be in the back of our net. It's a tough decision for me, I thought I tried to keep it within the rules, but I haven't seen the replay," he said.
"I've been down that road, it's a terrible feeling, I know (the Penguins) are probably going to want something to be done . . . (Letang) said he was good," Pacioretty added.
The Connectictut native, who scored his 10th goal in the game, has made a remarkable recovery from his own harrowing experience with brain trauma - at the hands of Boston Bruins captain Zdeno Chara.
But his actions beg a difficult question: how is the game to address blows to the head when even those hurt badly by them find themselves on the accused's bench?
Penguins superstar Sidney Crosby, playing on Canadian soil for the first time since suffering a concussion last January, didn't exactly provide clarity on the subject when asked after the game about his elbow to the face of Ottawa Senators forward Nick Foligno during a post-whistle scrum on Friday.
Granted, that incident paled in comparison with Pacioretty's hit on Letang, but Crosby is also being held to a higher standard given his prominence in the game and outspokenness about gratuitous head shots.
Foligno and the Senators publicly called out Crosby for hypocrisy following the incident, and on Saturday, Crosby shot back.
The gist of his argument: I knew what I was doing and it could have been worse.
"I don't know what he expects after he runs the goalie three times. He's probably lucky it was me that was handling it and not someone else so . . . I think if he's going to do that, he should be ready to expect a response. Like I said, that's a hockey scrum and he should expect that if he wants to play that way. Given the option to get my hands up the same way, I've got stick up for my goaltender as well. I'm sure he's okay. I knew what I was doing. I was in control. I think he's okay. He should be careful if he's going to do that. Everyone knows you can't touch the goalie."
When asked if that invites opponents to make contact with his head, Crosby replied: "How many times have I done it? Once. A guy runs the goalie three times . . . I don't think I'm known for that. It was an elbow, but I think he's blown it totally out of proportion. Two nights before that, I go in a scrum and I get punched in the head. I accept that. I'm going into a scrum. That's part of playing the game. If he's going to run the goalie, he's got to expect that guys are going to get their hands in his face especially around that area. So, that's totally different from putting an elbow in a guy's face coming across the middle. They're totally different circumstances. He's known for being a chippy player and trying to be an agitator and that's what comes with the territory if you're going to play that way. You've got to expect guys to do that, so, to answer your question, no, I'm not worried about it because I don't usually do that."
On the whole, Crosby would probably be happier to talk about more pleasant things, like his play on Saturday, which saw him net an assist.
So let's see, eight points from four games with 58 to play - at this rate Crosby will score a career-high 124 this season.
He'll also likely reel in the likes of Phil Kessel and Claude Giroux atop the NHL scoring chart around the time in the New Year where people are still writing 2011 on their cheques.
Add to that that the Pittsburgh Penguins have now won three of the games he's played since his return, and it's probably not too soon to start speculating about whether the Pens might still be playing hockey when next June rolls around.
Then you have the Habs, who have now lost four of their last six, are once again left to wonder how it all went wrong.
And it did go horribly wrong in what was a surly ending to a surly game, although the Pens' view will be that it was poetic justice.
The winning goal was potted by Letang - who got to a puck that Carey Price believed he'd frozen by his left pad and slid it home.
Price smashed his stick on his net and skated off in disgust as the crowd roared its disapproval with the referee's decision not to whistle the play dead.
Afterward, Price was incandescent with rage, dropping a few expletives.
"I clearly had my hand over the puck. Clearly," he said. "It's tough, we worked our asses off for 65 minutes and it ends like that."
Asked when the last time was he was that angry on the ice: "I'm pissed. It's been a long time, especially because we worked so hard for it, and then we go and have it shoved in your face like that, it's really frustrating."
"It was underneath my pad, I put my glove on it, and suddenly a stick came in and rammed at it, and it came right out into the slot," he said.
Crosby had 26 points in 19 previous career games against Montreal, but just a single assist in his last four games in Montreal and only four points to show from his last seven visits to the Bell Centre.
He duly added to that total in the opening seconds of the game, but this was a game that Montreal had well in hand, leading 3-1 late in the second period, and despite some strong play from number 87 in black, it was there for the Habs' taking.
Pittsburgh opened the scoring on the opening shift of the game when Crosby's astute pass sprung Chris Kunitz, the puck eventually came to Evgeni Malkin, who tucked it past Carey Price.
That was 21 seconds into the game.
The Habs came close to tying the game within seconds, with Erik Cole's one-timer drawing a good save out of Marc-Andre Fleury.
In the event, Montreal knotted matters before the game was two minutes old when Travis Moen gathered a loose puck in the Pittsburgh end as Andrei Kostitsyn foraged on the fore-check and ripped a wrister high past Fleury's catching glove.
The brawny Saskatchewan native suddenly has eight goals on the season.
Price held his team in it during a Pittsburgh power-play, making a save on James Neal that can fairly be described as miraculous - he also denied Malkin and Kris Letang on the same man-advantage.
Having survived, the Habs went ahead 2-1 on Pacioretty's 10th of the season, the big winger converted a nifty pass from David Desharnais, who had captured a generous Fleury rebound of a Cole shot.
Again, the goal went in high on Fleury's glove side.
The Habs should have made it 3-1 on the power-play but Fleury stoned Cole in the crease.
The Penguins thought they'd tied the game in the opening 90 seconds of the second period when Crosby took the puck away from Montreal's Josh Gorges and slid a pass over to Chris Kunitz, who deflected the puck home.
But the officials waved the goal off - one replay angle suggested Kunitz punched the puck in with his hands, although the Pens will argue the evidence wasn't exactly iron-clad that it didn't go off his thigh.
Montreal made it 3-1 midway through the second when his shot beat Fleury high on the glove side, rang off the post and bounced in off the netminder's back.
It tends to be like that for Fleury when he plays the Habs - just look at the heavily-favoured Pens' seven-game playoff exit against Montreal in 2010.
Pascal Dupuis would grab a goal back for Pittsburgh before the end of the second - though Crosby made the play by outmuscling the Montreal defence and screened Price as Dupuis' wicked turnaround slapshot went off the post and in.
Montreal had a chance to make it 4-2, but defenceman P.K. Subban opted to try and sell an interference call on a two-on-one rather than take the puck strongly to the Pittsburgh net.
There were several instances where Subban sought to draw the officials' attention to slights against him - it's the sort of thing that has made him few friends in opposing dressing rooms.
In the third, Montreal had another chance to kill off the game, but Yannick Weber's power-play backhander hit iron.
On the same power-play, Kunitz had his second goal of the night disallowed as he broke in on a short-handed breakaway - this was a much easier call for the referee, the winger kicked Price into the net.
Later in the frame with the teams four-on-four, Price made a crucial save on James Neal, snagging his quick shot on a magical backhand pass from - who else - Crosby.
Jordan Staal would tied the game with 4:30 left when Malkin sprang the big centre on a breakaway - he coolly out-waited Price and flipped a forehand into the roof of the net.
The stage was set for the dramatic finish.