Well, you can actually play a fun game with call forwarding techniques. Say, I have access to his wife's phone and Google voice number. You can set up forwarding on the Google voice number to the wife's phone. Then, from the wife's Google number, call CISA, who then returns the call via the forwarding, so it doesn't even go through the phone, it goes through Google. This is the same trick old timers would do with mail forwarding.