TIFU by showing login data during presentation

I was presenting my school project when my teacher asked if I could show him the source code. I said ofc, just let me login to the FTP server. I completely forgot that it was also shown on the big screen, and a random funny student logged in and tried to replace the index file with a joke file. Of course, he didn't want to make damage, so he made a backup. But this backup caused the problem, because he connected to the FTP through Windows Explorer (wtf?), and when he made a copy of the original file, it was renamed to "Copy of xy", but in a localized version, which contains special characters. Because of these characters, some FTP clients couldn't even connect, others just couldn't interact with the file. No download, no rename, no delete, nothing. After trying out like 8-9 FTP clients, I just remembered that I could rename it in PHP. Well, it got deleted instead of being renamed, but at least it wasn't there anymore. I have spent like half more hour with searching for a backup version on my computer until I found it.

TL;DR: showed FTP credentials during presentation on big screen, random student accessed and renamed a file, special characters in name fucked up the server, luckily I found a backup.