This user
looks like a deleted user, but unlike most (all?) users, they retain their username - usually a deleted user become user123456 or something random number.
Is this a bug? What happened to the user?
Note the date. There was a time way back that user names were not anonymized on deletion. That looks to have been added sometime post this user being deleted.
Relevant stack meta Why is this non-anonymous username on this non-migrated question greyed out and not a link?