I dont think he has to go because of that, that blame is squarely on BB. If anything, if he shows up this year because hes "innocent" he should be held to a very high standard, ie, you are late, you act out, you dont play. Dress, skate around and then go sit in the locker room
If they want to regain credibility with the remaining players, they have to. You can't let Kane stay after something like this when you didn't discipline him when it matters. The players know any attempt to keep him will be hollow.