There was indeed contact between McAvoy and Kampf's head, but McAvoy was already in motion for the hit when Kampf made a sudden move for the puck, leaving his head vulnerable.
Surprisingly, there was no penalty called on the play, indicating that the referees didn't see it as an infraction. Moreover, there hasn't been any response from the NHLPA regarding the incident.
This isn't the first time Leaf fans have accused Bruins players of questionable behavior in the series. With tensions running high, every game seems to bring new controversies and frustrations for both teams and their supporters.