I remember one of my maths teachers in secondary school was really, truly a genius, with many, many successful inventions to his name.
But utterly useless at teaching.
I remember one of our (better, TBH) chemistry teachers, bless her, dealing with us rowdy, adolescent teenage lads who had taken it a bit far one day, she went into a full on shouty rant about us not being hard, and that her old school in Liverpool had got burnt down by the kids, and the teachers frequently beat up, "but at least they had respect". That really was it for her then. Shame as I really liked her
Another not well liked teacher, on his last day, was stripped, shaved head to toe, and chucked in the pool. Worse punishment for this essentially full on assult? Most who had limited involvement got off scott free, those putting the boot in mostly got a hours detention, and a couple got suspended for a couple of weeks... ...over the summer holidays!