At the outset, I am in no way attempting to justify what Dunc did. There's no justification for it. It was patently against the rules and dishonorable (if that term means anything in playoff hockey). Dunc recognized that and apologized immediately. I give him credit for doing that. It doesn't mean the suspension wasn't warranted. It was. However, many of the same considerations that factored into the decision to suspend Keith are also present when evaluating Carter's conduct, albeit to a lesser degree. As such, Carter should be penalized as well, albeit to a lesser degree.
I think we can all agree that Dunc's swing was reckless. I take him at his word that he did not mean to hit Carter in the face. Kings' fans want to believe otherwise but I don't think either guy intended to injure the other. That said, they were both reckless. By reckless I mean knowing that their actions would have a substantial risk of injuring the other guy but they did it anyway.
Dunc was clearly reckless and clearly more reckless than Carter. Shanahan was right to describe the hit as a "One handed, upward swing toward the face." Even if he didn't mean to hit Carter in the face, Dunc has to be accountable for swinging his stick upward toward someone.
However, Carter's actions also displayed recklessness. He took a two hand chop down at Keith's glove and/or unprotected hand. Kings' fans are too quick to say Dunc wanted to injure Carter but Carter was just trying to hit Dunc's glove. I don't buy it. I think Carter knew Dunc was going to pick up his glove and threw a chop knowing Dunc's unprotected hand would be there. Just like Dunc should be accountable for doing something he knows is likely to cause injury, Carter should be accountable for that too.
Punishing the Outcome vs. Punishing the Act - The Injury
Carter required 20 stitches and dental work. Not good. Fortunately he was able to return to the game. He'll be in Game 4 as well. Those are good things. It means the Kings won't be robbed of their best scorer unfairly. Note also that the fact that Carter was injured was a "Key Point" in Shanahan's decision to suspend Keith. That's the outcome of Dunc's action.
But we don't only punish the outcome. We also punish the conduct. That's why players get penalties and suspension even when they're conduct doesn't cause injury.
Here, there's little doubt that Dunc's conduct and the outcome merit some kind of supplemental discipline. Personally, I feel one game was fair (I would have been ok with 2 also). However, I believe Carter's conduct also merits supplemental discipline but less severe than Dunc's. There are a couple reasons why.
First, Shanahan classified Dunc's high stick as, "a retaliatory high stick to an opponent that causes injury." An accurate description to be sure. However, let's break down the parts of that statement: (1) retalitation (2) illegal use of the stick (3) causing injury. Two of three also apply to Carter. If Dunc's was retaliation, so was Carter's. The two of them started their scrap by the goal and it continued up to the neutral zone where Dunc popped Carter. So anything Carter did was in retaliation too. Second, recklessly slashing toward opponent's unprotected hand while the puck is 100 feet away is also an illegal use of the stick.
The two main differences are that Dunc actually caused injury and the injury it could have cause is classified as more serious. As to the first difference, causing injury should result in more severe sanctions. However, either Dunc's or Carter's conduct could have ended the other's season. If Carter had broken a thumb or finger, Dunc would be out. It's not as serious as poking out an eye but it's not little thing to risk ending someone's season.
So we have several of the same considerations that factored into Dunc's suspension present in Carter's case too. Yet he did not receive any supplemental discipline.
History of Prior Offenses
Another of the key points that Shanahan enumerated was Dunc's status as a repeat offender. No doubt this is worthy of consideration. However, the shame is that Carter walks/skates away from a reckless play that could have ended an opponent's season without any "prior" to his name. Let's say next season Carter takes another reckless chop at someone's bare hand and breaks some fingers. It would be his "first" offense despite engaging in the exact same conduct previously, the only difference being actual injury resulted. That's the main reason why I would have liked to see the NHL levy a fine against Carter. I know $5,000 doesn't mean much to most star athletes but the next time Carter (or Dunc) loses his cool, it's unfair that Carter will be treated as first time offender.
The frustrating thing about all the Shanabans is that they often fail to account for the context of an action i.e. Shanahan rarely, if ever, metes out punishment to the instigator for his conduct even when that conduct is wrong in and of itself. Dunc should have been suspended. But Carter should have been disciplined too. Just less than Dunc.