In the beginning of the movie when Travolta and Slater are boxing, Travolta throws a final upper cut (shown in slow-mo) that T.K.O.'s Slater. Watch carefully as Travolta's boxing glove comes up fully in front of Slater's face (going almost past the top of his head). Clearly, it never touches him (Slater) at all. But what's even worse is that as Travolta's boxing glove reaches the same height as the top of Slater's head, only then does Slater (finally) react to the punch by throwing his head backwards. And he does so in such a way that it makes him look as if he were hit directly on the chin even though Travolta's boxing glove has gone far beyond that point by then. I know that they are not really hitting each other. After all, it's just a movie. However, my understanding of how scenes like this are done is that the camera angle and distance (relative to the actors) are suppose to be set so as not to give away that fact that they are not actually making direct contact with their punches. I think that the combination of the punch being shot too close up, bad camera angle, and the fact that they chose to show the punch itself in slow motion made this slip up stick out like a sore thumb.