I was in the team of technical support staff at a web hosting company for several months, in that time people made simple mistakes, but this is just stupid:
Client: I'm having some problems updating the homepage.
Staff: Okay, what seems to be your problem?
Client: Well, I upload the file that I want to be the homepage, but it does't update the main site.
Staff: Are you sure you're uploading the file into the website director? The folders you should be uploading are called either "www" or "public_html"
Client: Yes, I can see the file in that folder
Staff: Strange, try uploading into that folder again.
... ... ...
Client: No, it still not updating.
Staff: Hang on, I'll take a look at your files
... ... ...
Staff: I've moved one of the files into the public_html folder. Does your site look correct now?
Client: Yes thats right, but can you get rid of that image in the center, I didn't put that there.
Staff: Sir, that's the file you uploaded, I haven't made any modifications to it
Client: Oh right, well change it back to the original file.
Staff: I can't do that sir, there isn't such a thing as "Undo" in webhosting
Client: Why not? Change it back now.
Staff: Sir, we are not responsible for your site backups. This is out of my hands
Client: Oh, thank you