Weird behavior after deleting (!) accounts

[Denis Brooker]

There were quite a few accounts on our MySQL database that started with (!). The explanation was "<account> does not exist but it still has privileges defined for the following objects:” Based on the information given and another post in the forum that said "The message you get comes from the fact that there are grants for a user which no longer exists. So it makes sense to remove those grants.” However, when I removed the account, it affected an active user (another account) by removing the grants for that user. The two accounts (the deleted one and the active one) had the same name but were different accounts from two different hosts. Has anyone seen this behavior before?