I actually think it's pretty sad as it is - but if there was any seriousness about it being based on reality - that would be dreadful. Anybody who acted remotely like that would be held for assault - and if there was any truth to the burial, well they'd be murderers! If anybody is seriously that angry as a teacher, then they are in the wrong field - to say the least!
I know, however, that in the old days (like 50 years ago, I guess - although I wasn't around) the strict teachers (I've heard of many nuns doing this) would rap students on the knuckles with sticks if they used flat fingers and tie them to broom-sticks to keep straight backs. No wonder many people left music lessons as soon as they could.