The oddest thing that has happened to you during a performance.

In my Grade 7 piano exam I went to turn the page in my B piece and the music fell off the stand and landed in a heap on the floor. I swore quite loudly, then panicked and just turned to the examiner looking like a deer in headlights. She said "it's alright, just pick it up and carry on." which I did and got a pass level mark for that piece (and the exam overall) so she clearly didn't hold it against me, thank goodness! In my defence that piano had seen better days, still serviceable musically but a bit battered and the music stand was extremely wobbly.

In my Grade 4 viola exam I was so nervous that at the end of the first piece I dropped my bow. It finished on a very long note and my hand was shaking, I went to lift it off the strings and it just fell out of my hand. Thankfully it was still in one piece, the accompanist and I had a little chuckle about it and all was well.
Lol. Looks like exams make you nervous but then who isn't. Some are just confident while most of us are the nervous wreck.

I guess your teacher understood your situation and the stress.

Thankfully, I haven't had such a clumsy moment when it came to musical instruments.
This happened recently but not to me. A close friend of mine was chosen as interpreter of a finalist entry in a songwriting competition. We were expectant of a win until my friend forgot 2 lines of the song. He said that he got confused with the teleprompter because he is not used to it. That's a neat lesson to be learned when performing on the stage.