The source was a pupil who didn't like the assessment awarded to him, and whose parents threatened legal action unless it was changed. Sometimes the difficulty in finding those responsible can lead to stalemate, but an influential parent or inactive headteacher can also result in misery for the teacher.
By chance I passed through the nondescript town in eastern France this summer where a relative had completed her year abroad. The school was full of pupils not the least interested in learning anything, never mind English, and the result for several months was great difficulty for the student teacher, fending intellectual remarks like "What is your bra size?" from adolescent boys whose regular teachers had long since given up on them. Only an ultimatum that she would refuse to teach the class unless she was backed up resulted in any action from the head.
At home I remember one teacher whose car was deliberately scrtched four or five times over a period of months. It all arose from a fallout in the geography class earlier in the session.
I can only recall one malicious act of revenge to affect me personally. Our school runs a Friday activity afternoon. Tenpin bowling is oversubscribed, and I help with it. Last year the man in charge at the desk where the shoes are issued asked if there was a Mr Maclaren from the school present. He had taken a phone call to say that my wife was in hospital after an accident. He had no details, but as the school was only five minutes from the bowling alley I returned as quickly as possible.
No one at school had news so I phoned the Southern, the Victoria and the Royal Casualty Departments - all in vain - before I thought (for the first time, in my panic) that there was something strange about the situation. I phoned home. My wife answered. It had all been a hoax.
Yet had I happened to phone five minutes before she would have been out . . .
Colleagues in school were very sympathetic, not least at the cleverness of it all. I inferred that it must have been a pupil refused admission to the bowling, but there was never any proof. I'm applying for embroidery next year - you meet a nicer class of pupil.