Thanks, it looks like the file was removed already.
CentrifyDC 5.1.2-378
It looks like this client has not logged in to this server since May of 2015. They are able to login to other servers and other folks are able to login to this one. So the problem appears to be isolated to this ID on this server.
There are no deny or allow entries in the sshd config. The server has been up for a little over 3 months and SLES updates have been applied since they last logged in, but if the issue were those updates it would have disabled logins for all rather than just one.
Since the ID is enabled for AD authentication the usual Linux commands for resetting the expiration do not work because it is an "Unknown user."
# chage -l <userid>
chage: Unknown user `<userid>'.