But if it was the other way around and you were the person that didn't stop to help, you would begin to analyze and explain your own behavior and motivations, then you would tend to think the opposite of what attributes to others.

Research of fundamental attribution error shows:

in cultures like US, its common to describe people's behavior to personality.
people tend to describe their own behavior to situational more than personality.
in cultures like China, people make the same fundamental attribute errors, but not as cultures like US.

The research shows individuals decide whether their own actions are influenced by their personality versus situational. People decide "other group" to individual members attribute, yet the decision of their own group to the collective group rules.

People can't stop this functional attribution error even when they know they are doing it and its wrong.