[gexla]

Says this...

Type :qa! and press <Enter> to abandon all changes and exit Vim

Maybe not quite what the user was looking for. But I guess it does get you out of Vim.

ETA: Also, that answer on Stack Overflow at one time was the answer with the most traffic on the site. Reading must be a common problem for trapped Vim users.

[recursivecaveat]

I think abandon-changes is probably the best suggestion for most people in that situation. If you don't know how to exit you've probably made some accidental changes.