How does Dill react to the happening in Chapter 19?

When Mr. Gilmer questions Tom, he does so fairly aggressively, addressing him only as "boy". Mr. Gilmer tries to get at Tom's motivations for helping Mayella, insinuating that he must have had ulterior motives for helping her. Tom finally says he just tried to help because he felt sorry for her, which stirs up the audience considerably, as it is unacceptable for a black man to feel sorry for a white woman. Mr. Gilmer asks whether Tom thinks Mayella was lying about asking him to chop up the chiffarobe in November. Tom avoids a potential trap by saying he thinks Mayella must be, "mistaken in her mind" about this and everything else. Mr. Gilmer asks why Tom ran if he had a clear conscience, and Tom said he was afraid of being tried in court, not for what he did, but for what he didn't do.

At this point, Dill starts to cry, and Scout takes him outside the courthouse.