Harvey "Two Face" Dent: Batman's only limitation is his reluctance to kill another human being. Good thing that Harvey died from the fall off the building where he was about to kill a helpless child.. or else Batman would have had to kill some Dent butt. Yes, Batman did do the pushing here, but it was not his intention for Dent to fall off the side of the building foundation. Hence.... accidental death!
Thanks to Gaby!
Clayton: The last fight between Tarzan and Clayton is kinda violent. However, Clayton does not die at the hand of Tarzan. It was his own fault. He was too busy trying to slice Tarzan to notice the vine around his neck, and he's hanged. The shadow of Clayton's hanging body at the end really pushes the G-rated limits too...
The Evil Queen: She came close to being killed by someone else! Those dwarves were trying to seek out some justice. But lightning strikes and causes the cliff she's standing on to crumble. She falls before anyone can touch her.
Gaston: He is such a tool. I always want to see the Beast just drop him off the tower of the castle. But the hero can't kill the villain. This is Disney. Gaston apparently forgets that he is dangling off of a balcony and lets go of the railing in order to take a swing at Beast. And you know what happens next.
Maleficent: Prince Phillip almost got her! You know, with that sword and all. But I'm pretty sure falling off the cliff after lunging at Phillip did the trick. So, it was her fault. Also, I've always wondered how Phillip dodged her huge dragon body and didn't fall too. Now when you watch Sleeping Beauty I guarrantee that's what you'll be thinking.
Frollo: With Quasimodo dangling from the bell tower, and Esmerelda desperately trying to pull him back to safety, it would have been hard for either of them to murder Frollo. However... luck was on their side when the appendage Frollo is standing on suddenly breaks off the side of the tower. He falls down, down, down, into the hellfire.
Mother Gothel: She falls. Out the window of Rapunzel's tower. This one is debatable! You could say that Rapunzel's lizzard killed her because he went and tripped her with the hair. But I think that in the midst of freaking out and pulling her hood over her head, it was her own fault.
Charles Muntz: I don't really know what is going on in the scene where he dies. It moves really fast. But I know he leaps out of HIS OWN free will, and falls.
This list is FULL of spoilers.
Movies where the villains die on accident, and not at the hands of the hero. I've noticed it mostly in Disney movies, (murder wouldn't be very G-rated would it?), but there are bound to be films where the bad guy dies in the same sort of manner. I'm open to suggestions!