InvalidParameterException - File profile/tiny.jpg (0) is missing an owner!

OK, I've been breaking down the problem described here, and I have a more specific question.

Other than my own login problem, the site seems to be working fine, EXCEPT this error I believe I have caused by deleting a user who was a member of a group. Now I can't load the group page because, I suspect, it is trying to load said now nonexistent user's profile pic.

Is there any way I can look up this file on the database or file system end, and delete it or just give it a different owner?