I cannot remember any instructor pulling their punches with me, ever.
I can only recall one instructor "having it in for me", but this was balanced by another instructor who was aware of the bias and fought my side behind the scenes.
I do recall that the BFTS debrief sheet had a backside that the student did not get a copy of. I also recall that the students knew the combination of the cabinet in which these confidential sheets were kept. One duty student, call him John, doing the lock-up was in dire straits flying-wise, and could not resist the temptation to open up the cabinet and peek at his most recent confidential trip sheet. It began with the words "Do not read this John, it will depress you..."
Turned out the combination had been known to students ever since that QFI was a student.