I cannot "beat" anyone at all. I am incapable of using it, therefore I cannot choke Ms. Maryellen.
Tom is explaining what really happened. All the white men ,of course, didn't agree with anything Tom said. The all white jury declared Tom guilty. Even though Tom Robinson was wrongfully accused of raping and beating Miss Maryellen, he was still put in jail before running away and being killed. The real culprit was Bob Ewell as the bruise described marks on the left of Ms Maryellen. Bob was also left handed as Tom Robinson was not since he tore all his muscles in that hand. Later in the book you find that Bob tried to kill Jem and Scout. Bob severely hurts Jem but not Scout. All of bruises on Jem were on his left side. Clearing indicating that Bob was the person who beat Ms. Maryellen all along.