Chapter's 16-19 in the perspective of Bob Ewell

I took my seat facing Judge Taylor and could see Mayella quivering in her seat. I turned around and saw that people were already crowding the seats and the Negroes were standin' on the balcony.
"Mr. Ewell, you do remember the arrangement of the story right?" Mr. Gilmer whispered to me.
"Well, yeah, just about."
Mr. Gilmer nodded in approval as Judge Taylor called the court to order. Heck went up to the stand first and was asked what had happened that day on November 21st. Heck seemed to help our side of the story well enough. Next up to the stand was me to be asked questions by Mr. Finch. Mr. Finch asked me what I had been doing on November 21st and I answered with a story that seemed to go along extremely well with Heck's. The smirk look on Atticus's face made me wonder if he had caught something but I told myself not to worry and paid attention to his questions.
“Just one more question if I may, Mr. Ewell?” Atticus paused as if waiting for approval and I nodded in acknowledgement.
“Can you read and write?”
“Well of course I can,” I answered.
“Would you write your name for me, please?” His taunting politeness was getting to me. He handed me a blank envelope and a fountain pen and told me to write legibly, which I took to offense. I took my time writin' and peeked up at Atticus only to see that he was intrigued in the way I was writing.
“Well, what's so interestin'?” I asked.
“I've noticed you write with your left hand,” Atticus pointed out. He seemed to have made a point to the judge but I was red in the face with humility 'cause I didn't know what me writing with my left hand meant. Mayella seemed to be thinkin' the same thing.
“Are you ambidextrous then, Mr. Ewell?” Mr Gilmer asked. Who was he to think that I couldn't use my right hand, how dare he.
“I most certainly am not!” I declared.