During the last couple of minutes when the 30th floor is going to hell. MaClane is in the fountain. He goes under the water when an explosion forces him down when he comes up he shakes his head, But it's not him look close. No receding hairline and a narrower body. Stunt-man
This is something you can see throughout the first two Die Hard movies. You can see Bruce's stunt double fighting in almost all fight scenes, if you look closely. When he ends up fighting that guy on the roof where all those pipes are stacked up, you can see the double a few times. In Die Hard 2 when Bruce follows the two terrorists in a back room where the luggage conveyers are you can see Bruce's stunt double quite a bit. It's like they didn't even bother to try. Maybe Bruce was on lunch and they decided to shoot the scene anyway. Numerous times in the two films, during fight scenes especially, Bruce's stunt double can be seen taking the brunt of the fake punches, etc. Many times, in wide shots, Bruce doesn't even do a simple stunt like take a fake punch. Makes me lose some respect for the guy.