We had one who copied and pasted a piece on a film star. The classroom teacher didn't spot it - and it was obvious . It was the one year that I didn't have the time to check every single folio piece myself. (That still annoys me. DH was perilously ill after surgery, so I couldn't stay in school until late as I usually did at folio time, so had only checked the Higher pieces myself.)
The SQA required the school to conduct an investigation and the findings were sent to the board.
This was when we had our old (good) HT.
On results day, Mummy phoned in to complain that there was no grade for English on the certificate.
"Well, Madam...Would you rather it said 'Cheat'?"