Continuity mistake: When Jack is having his Santa joyride, the army is called in to shoot him down. There is one sweeping shot of the giant cannons rising and firing at him. If you look at the bottom of the screen, you can see two small soldiers as the guns are rising, but as they fire, the soldiers blink out of existence. (00:58:30)
Answer: Except they're a reanimated corpse and a skeleton. They are either already dead (or undead), or, given how things seem to work, the normal natural laws don't apply to Halloweentown.
Greg Dwyer
But how did Santa survive the Iron Maiden? Especially with how big he is, he certainly would have been killed.
You're trying to apply the rules of the real world to fictional magical beings.
LorgSkyegon