Answer:
Scout realized that Tom had no idea about the consequences of hitting a white woman.
Explanation:
Tom had hit a white lady, probably out of anger or frustration and didn't know the implications of striking a white woman (Tom is probably black) so after realising what he had done, he immediately took to his heels because he would be probably tried and executed.
It's clear that he acted without thought and was driven by anger before he proceeded to strike the white woman.
