Steven Zahm@ Matt
I looked at the links in the db, there are no other duplicates. I would expect if there was an issue with other users not being able to edit their entry that there would be duplicates or links to non existing entries/users. I did not find any, which is good.
I tested the user you mentioned… using the User Switching plugin, I was able to switch to the user and make edits just fine, no errors. The edit caused it to go to moderation which is expected due to the role capability settings.
I suspect the user misinterpreted the moderation notice as an error (or maybe not) and requested that the change be approved by the site owner and the site owner misinterpreted her request as her reporting an error.
So, the short version, I can not find any issues other than the issue you experienced with the test user.
If you can recall which steps you took to end up with a broken link to a non existing directory entry, I will definitely take a look because that is a bug because that should not be possible.