When Phoebe, Monica and Rachel were out on the balcony, Rachel knocks her pillow over the edge. That wasn't really supposed to happen, but they left it in anyway.
Matt Leblanc named his favorite all-time "Joey" moment in this episode when Joey childishly pretends at the hospital that the hockey puck is repeatedly coming straight at his head.
In the DVD version of the episode, the girls also discuss what Chandler, Joey and Ross (much to Monica's protest) are like in bed.
In 2002 the NHL installed mandatory safety netting following the death of a 13 year old fan at a Columbus Blue Jackets game in order to prevent injuries similar to Ross's.
There is an extended version of the scene when Rachel first sees her old friends and it is implied that Kiki is bulimic.