Jason Zucker crashed into the end boards after an awkward collision with Mark Stuart. As Zucker was down on the ice, Stuart made sure he stayed there be shoving him repeatedly in the back. The whole scene was rather uncomfortable as it was clear on the broadcast that the mostly motionless Zucker was in rough shape.
https://www.youtube.com/watch?v=kIMSwdDVBXc
Zucker left but later returned to the action. As for Stuart, no penalty was assessed on the play.