Not so long ago I failed a PPL because of a number of reasons, and when we got on the ground and he asked me to sign his logbook and I said no then taking him into a class room and telling him where he went wrong the bloke then went and blew his top at the CFI about me...
All I wanted to do was stop the bloke killing someone else...
The crap we all have to put up with off PPL holders is unbelivable sometimes, they think they can act like heavy metal pilots and shout when it does not go right!
Cheers
SJ's