Thanks for the bug report HostPhenom.
Confirmed on my version, I've uploaded a fix to the modules site as 1.0.1 that should fix all issues with the services crashing on the close command. Please let me know if you continue to have issues with the module.
The new behaviour is the desired effect - If no username is specified and the user is a HelpServ operator, it will look for a ticket with the oper's name. This is the same behaviour as that which regular users have. Adding a nickname will still close the user's ticket if the user is an oper, as before.
Again, thanks for the report.