In light of this mistake, wouldn it have been fairer to leave Pirates of the Caribbean: Dead Mans Chest on the corrected ballot?
When the error was discovered, we considered various ways to address the error, including this option. Ultimately, the Hugo Administrator, in consultation with senior members of the Nippon 2007 committee, decided that adding Pan’s Labyrinth and removing Pirates of the Caribbean: Dead Man’s Chest was the best way to comply with Hugo voting rules and respect the will of the voters. Your mileage may vary.