Wo Fat's assassin (played by Robert Nelson) is named Chow Lee. In subsequent appearances, his name is Chong.
No plastic surgery could make a precise duplicate of another person's face.
When the car containing the injured McGarrett is rolled over by the tow truck, there is no engine or transmission in it.
When Wo Fat & his henchman are watching the press' interview with the governor, they see the interview from an angle where no press have been shown to be, rather than the viewpoint of the television station camera operators.