The Florida Panthers were penalized after their fans threw a bunch of plastic rats on the ice. Apparently two goals by the same player is a "rat trick" in Florida because of some old boring story about a dude killing a rat with his stick and then scoring two goals with it.
Seems like a pretty stupid thing. But the Panthers deserved the penalty minutes for giving out the plastic rats. Why would you bring back a tradition that you worked so hard to get rid of?