It happened when I was a student at the laboratory defense in physics. All the calculations were done at home, and the defense answered a bunch of questions on theory. We did lab in teams of 2 people, and defended together, both.

This lab was done independently of each other, but the experimental data were the same (i.e. The solution is one for two). And here is the moment of defence, it is tight, the topic is complicated, the teacher just won't let the defence go, but by joint efforts we manage to answer enough for the count. Here we are already in the journal noting this defence, they write up and here my comrade issues: "You know, we only got answers in the lab completely different...".

I don’t even know how to describe the mix of emotions I’ve experienced! Prepod slowly raised his head on us, looked closely and said, withstanding a good pause: "Well, I have already scheduled."