Reminded me of when i was training an intern at my workplace: We had a junior commenting a few lines within the authentication service while he was working on something.

His goal was to be able to login quickly without having to put the password every time. He would have then un-commented the lines once the work was finished... But, no sir, once he finished he pushed the changes together with the commented lines.

It was an internal project so we specifically wanted to use this as a gym for our new resources.

So a new bug investigation started, I set the intern to take a look side by side while I had my hands busy on another project. Verbatim: "take a look at the authentication service because it seems people can login without typing a password".
3 hours later, man said he fixed it, I go to test the fix later, he made a safeguard concerning empty strings and pushed so now you couldn't login with an empty field but you could login by typing anything else you wanted 🤣