Wordfence reports incorrect user login

Yesterday we had a big scare because Wordfence reported a user logged in and showed a ip address which wasn’t ours. Apparently it was a staff member using Manage WP to log in to the site so the IP address didn’t show as ours. Reviewing the former email login messages this hasn’t been the case in the past. The big problem is it showed the user name incorrectly and one that isn’t even in our Manage WP setup. How this error occurred is beyond me but for a while it sure looked like someone had managed to hijack a valid user and password. I’d like to know if there have been any other reports like this.