Many Pokemon fans have heard of the episode where Charmander falls into the ocean, but somehow his tail flame is still burning. The water should have put out the flame and Charmander should be 'dead' (or as dead as a Pokemon can get) but it goes unexplained.

In this movie, Charizard's tail flame goes out too, except you actually see it. It's brief, but you don't need frame-by-frame to notice. When Mewtwo brings out the first clones of Blastoise, Charizard and Venasaur, eventually Charizard is the only original that hasn't been defeated by the clones. Ash tells Charizard to go against the Charizard clone. Charizard roars and steps forward. His tail swings behind his back, and for a moment, it's clear that the flame goes out. You need to be watching the tail. Sorry for lack of excitement.