If this is an automatic, did he try cranking in neutral? Have him turn on the headlamps then turn the key to crank, see if there is any reaction from the headlamps, do they dim-- go out-- stay bright no reaction? If they stay bright, sounds like an open circuit to the starter.
Also, he could use a jumper at the starter relay. Make sure the tranny is in park or neutral and a functional e-brake is set. Key in the on position, on is where the dash lites come on, pull the starter relay, use jumper wire between terminals 30 and 27, where the relay plugs in, the starter should crank. Don't leave the jumper hooked up more then a few seconds. Don't know how experienced the person is as far as working on vehicles, if he isn't comfortable with this testing, then don't test.