Not sure why, but it turned out that there was something corrupt with his ID on his own PC. Not the Citrix station. We could sign in as someone else into his Workstation and then have him sign into Edwards and everything worked correctly. If he signed into his Workstation, no matter who signed into Edwards would get the failure.
Because we are in the process of swapping out Workstations, we just swapped his out a bit earlier than planned and everything is working fine now.