Tom makes a fatal mistake in his testimony to mr gilmer saying he felt sorry for Mayella. Why was this the wrong thing for Tom to say?

It was unheard of for a black man to say he felt sorry for a white woman, no matter her curcumstances. The all white jury, as well as the all of the white spectators in the courtroom were offended.

“You felt sorry for her, you felt sorry for he?” Mr. Gilmer seemed ready to rise to the ceiling.
The witness realized his mistake and shifted uncomfortably in the chair. But the damage was done. Below us, nobody liked Tom Robinson’s answer. Mr. Gilmer paused a long time to let it sink in.