The play occurred late in the 3rd period the Bruins already trailing 6-2. As Staal throws the puck around the back boards, Nosek then closes the gap with the puck clearly out of sight and delivers the elbow directly to the face of Staal. The elbow sent Staal to the ice and ended his night.
On the play somehow the officials assessed no penalty, despite the deliberate nature of the play. However, it's expected that Player Safety will review and issue a punishment for this hit. It's hard to believe that if Bunting received 3 games that Nosek won't be looking at a similar punishment.