She's emotional cause she lost her job and is in a bad way compared to you. Honestly, she's abusive as well. If I was a father, and a teacher made my child miss lunch multiple times, they're gonna have a huge problem. Brush the asswipe ex teacher aside and leave her in her pile of shit. But seriously, I've had to make up assignments multiple times. Why didn't the teacher just let your son work and eat at the same time?

why was your son's former teacher even contacting you, sounds like she has some petty vengeance to deal out and the school board already laughed her off. don't respond to it, ignore and move on

I've done schoolwork through lunch a bunch of times and I promise it never killed me. Everyone is a bunch of pansies these days. Like, missing lunch every day would be bad, but every few months, I can't imagine getting upset over. Depends on the age of the child. Sounds like an older child, if it was my kindergartner, on the other hand, I would be irate. Weird situation.