Regarding Bunting. If he had been injured then yes, automatically he comes back in regardless of how the team or Knies is doing (if needed, sit someone else).
To me, all bets are off for a suspension after a dirty hit, and it's an easy explanation from Keefe - even easier if the Leafs are rolling when Bunting is set to return - "I can't risk putting you back in that you'll do it again." If they lose then that's an excuse to get him back in, but if they keep winning he can't sit indefinitely either so ...
I can't say I'd blame Keefe for putting him right back in, even if Toronto is on the verge of winning the series. The argument being that the 3 games was punishment enough and he's clearly an importnat part of the team. Just make sure he understands he's on a short leash and has to keep his emotions in check. If he so much as takes a bad penalty, bench him and he's in the press box the next game.