Flying a Mooney. Wow. That's like what, the Jaguar or maybe Harley of US aircraft, some incredible planes but tortuous company history. The kind of plane that could survive a forced landing (monster airframe, retractable gear) if he found a meadow up there: let's hope so.
Latest Mooneys have some really cool Garmin avionics and 1500 -2000 mi range, so being so far off a direct course to Mammoth may not have been an issue. This one is going to be interesting.
Hoping for the best.