(See post below for explanation)
Let me set the stage for you, it's the 1998-99 NHL playoffs and every goal that's scored is being reviewed by a team of CSI experts to see if anyone was in the goaltender's crease. These were the days when the lace of your skate couldn't even graze the outside of the crease or a goal was disallowed. You could be on the other side of the net from where the goal was scored, nowhere near the goalie, with a fraction of your toe in blue and the goal wouldn't stand. The rule was, if you were in the crease and the puck wasn't, you were guilty and you feel shame.
Now look at the above photo and tell me how the goal that Brett Hull scored a split second after the photo was taken was legal. He was in the crease and the puck wasn't. No goal, right? Wrong.
In triple overtime of game six of the 1999 Stanley Cup Finals Brett Hull scored this goal giving the Dallas Stars the Stanley Cup. He's the one in green, with his foot and half his body in the crease.
The official explanation from the NHL was,
"A puck that rebounds off the goalie, the goal post or an opposing player is not deemed to be a change of possession, and therefore Hull would be deemed to be in possession or control of the puck, allowed to shoot and score a goal even though the one foot would be in the crease in advance of the puck." (from http://proicehockey.about.com/od/history/f/no_goal.htm)
Because Hull got his own rebound, the explanation says that's it's as if he never lost the puck.
At the very best it was a terrible rule that has now thankfully been abolished. At the very worst it was a pretty sad way to win and lose a championship.