Kadri is a little rat weasel, always has been. That being said, they came away with 4 minutes of PP, regardless of whether they scored or not, playing 4 minutes on the PK, under normal circumstances, means not only to you have to endure pressure, but you also can't put any pressure on the opposing team. In a butterfly effect world this could potentially mean this may have won the Leafs the game by simply making sure the Rangers have less of a chance to score for about 4 minutes.
What IS concerning though is that the player behind McQuaid (was it Nylander?) did not jump MCQuaid from behind to hold him back. Not sure what to make of it, I'm not aware of Kadri's popularity in the locker or if this is just a case of the Leafs being too young and inexperienced to jump in.