Has a commit ever failed because of a problem with the editor?
$ git commit error: There was a problem with the editor 'vi'. Please supply the message using either -m or -F option.
Well, it must be a pain to rewrite the message again.
But if you saved the message before quitting the editor, it should still be there:
$ cat .git/COMMIT_EDITMSG
This means that you can commit without having to rewrite the message:
$ git commit -m "$(cat .git/COMMIT_EDITMSG)"