Thanks Tor. I was able to shutdown the server from the Terminal.
The output of id smithfi2
is:
uid=508121482(smithfi2) gid=1152591118(DOMNAM\Domain Users) groups=1152591118(DOMNAM\Domain Users),12(everyone),20(staff),12(netaccounts),29(_appserverusr),80(admin),81(_appserveradm),98(_lpadmin),201(com.apple.sharepoint.group.1), etc...
(Real username and domain name are of the same character length and alphanumeric format)