It's unlikely that she'll every get a teaching job again so it's not really necessary to strike her off. Some teachers are just bullies who get their kicks from being nasty to little kids.
Dancairo, if we carried on doing what we've always done then we'd never make any progress. Lots of children suffer verbal and physical abuse and it does harm them and they're the ones that misbehave most. What that teacher did was bullying and children learn best in a safe secure enviroment where they feel confident to speak.