Early in the second period, the Bruins appeared to have tied the game when Patrice Bergeron scored into an empty net.
Why was it empty?
Chad Johnson was behind the net, taken out by his teammate, Mark Giordano...
...who was pushed into the goalie by Brad Marchand.
After Calgary challenged the play, the goal was called back.
Take a look:
And from the NHL rule book:
What do you think? Right call?