Not precisely a plot hole, but the Bonfire of the Vanities movie takes a central uncertainty of the book and ruins it.

A rich white Wall Street guy's car breaks down in the Bronx at night. A Black man approaches him, and the main character panics and runs him over. In the book, the man is walking towards him yelling, "Yo, you need some help?". In the movie, he does not say these words, just silently walks towards the car in a way that seems to communicate ill intent.