I'm pretty sure I've used the 'uploaded the file by mistake' Because.. well, because I made a mistake.

Most commonly, when uploading from twitter, I'd change the url so I could get a preview then forget to change it back.

Whoops. I uploaded the wrong file by mistake.

I also want to say that I read somewhere??? that if you used that option after accidentally uploading an inferior version, it wouldn't count against you.

....

If I were to change the flag page, I'd:

• Change the first option to something more user friendly
• Use periods at the end of EVERY sentence, not just some of them.
• expand 'trace' to 'trace or copy' or something
• Change "I"m the uploader" to something like "other" with a note that disliking an image or it's content is NOT a reason to flag this
• Alternatively, explain the types of reasons why this option SHOULD be selected

...I'd probably also do something like include an option for "don't like the content" and it redirects to the 'how to use blacklist' page ;)