Over the years I've had several occurrences of multiple unrelated problems in the one flight, so it does happen, and as Old Fella says, sort of, "Some days I'd wished I'd stayed at home". But I hadn't and the problems were all dealt with in a satisfactory manner.
That's still no excuse for overloading a trainee until you find the breaking point, if the seats were swapped and the trainee was givinig it to the trainer his breaking point would also soon be found. No pilot is immune.
I once saw a very overloaded trainee give up and nose the sim over and deliberately crash the thing. A totally wasted sim session, a demoralised trainee, who was actually quite a competent operator, and an instructor who had to rerun a session and explain his actions to his boss. I couldn't, and still can't, see the point of it.
Regards,
BH.