Agree to disagree about the hits.
My belief is that Sundqvist's hit shouldn't be a penalty, bit it *is* in today's NHL. Somewhere in this thread (it was the Hyman on McIvoy hit earlier in the season), I chewed into 'the game' for not teaching players how to TAKE a hit. That's sorely missing from this game. Defenders routinely leave themselves in vulnerable positions - and that's exactly what Grzelcyk did (plus losing his balance). Earlier in the period, I think it was Carlo, was in the same kind of position, but protected himself appropriately.
It absolutely blows when the actions/movement of a defender is the cause of a penalty. Totally unfair, but it is what it is. See, 1/3 of NFL hits (and one reason why I gave up on the NFL). Players passed the responsibility of protecting them to the LEAGUE instead of owning it themselves, and now that is bleeding into the NHL.