The dumbest rule in hockey, and one that should be changed ASAP, in my opinion is the rule that nullifies a powerplay if the attacking team scores during a delayed penalty.

Why should a team lose their powerplay just because they were able to score while having the same number of players on the ice as their opponent? If a team can take advantage of being able to pull their goalie, they shouldn't lose out on a powerplay.

Take this situation. A player is going in on a breakaway with the opposing defenceman right behind him. The defenseman give the player a nasty two hander across the hands which the referee raises his arm to signify a penalty. The player shrugs off the slash and beats the goalie for a goal. Since he scored, the penalty is nullified but the player would have scored regardless of the slash. Shouldn't the defenceman pay for his offence?