Well some things never change.
Call is guy cannot communicate with his PBX. We recommend removing the IP connection (thinking some communication issue between the PBX and external device might be causing the problem).
The tech FLAT OUT REFUSED.
He said there is no network problem and he will not troubleshoot anything involving the network.
"OK," I tell the engineer who came to me for help, "ask him what troubleshooting steps he would like to take, and then tell him to go for it."