I accidentally overwrote /etc/passwd once and I allowed /boot to run out of space during a kernal update and I created a local user with the same user that was also on the realm/domain that I had joined and various bash script issues.
Some stuff I've had to fix that someone else did:
named a file rm -rf
rm -rf /bin instead of ./bin -- Also the fact that they had sudo was crazy and also I guess this was the second time
chmod -R 777 /
Various software bugs running swap out of space or hitting the inode limit by creating files over and over again with a timestamp in the filename and having to remove all of them because there was no backup to the OS
Someone disabled SELinux because something wasn't working but didn't tell anyone -- ugh
Compiled java because they googled some issue and followed some old tutorial without understanding anything instead of using alternatives and symlinked the old java from /bin to /home/theiruser/java -- had sudo because he was a Windows domain admin.
Cybersecurity guy didn't know what some VMs did so he turned them off and figured he'd find out if/when someone complained. Caused a massive core services outage.
Same Cybersecurity guy deleted a bunch of data because he wanted to see how the sysadmins would respond and witness backup restorations. He did not inform anyone.
Cybersecurity guy above still has Domain Admin and sudo everywhere. I would have personally removed his privileged access regardless of what 'CyberSecurity' management thought but I was leaving for a new job by then anyway so I figured I'd just let them eventually lie in the bed they made.
There's more but I don't want to keep going because it is Sunday and I don't want to ruin it.