About the theory in the "a sound of thunder" film?

Question

ok, im aware of the butterfly effect and the whole evolution bit. But im referring to the part when the butterfly supposedly affected the volcano eruption to be 5 minutes earlier. so answer either question( i dont know which one was suppose to be true in the movie). How could a butterfly affect something out of its control, like a volcano eruption: especially since the group went back to the exact time, how did the butterfly alter the volcano? any other possible inaccuracies in the film?

Answer 1

This was supposed to illustrate a subtle effect on evolution of the removal of the butterfly from the ecosystem.  The effect was that the computer was no longer able to calculate the arrival time correctly.  The system then delivered the next group to a point 5 minutes LATER, when the Allosaurus was already dead, and the volcanic eruption beginning.  This was the first, almost unnoticeable "ripple".  The ripples were written into the screenplay for visual dramatic effect.  Bradbury ended the story with the return of the first offending group and the possible murder of the offending member by the guide.  Of course, everything they tried to rectify the situation only made it worse.  They couldn't fix it because they didn't, and if they had the movie couldn't have been more than one scene long.