I have no reason to doubt Woz, but what's the point of yet another claim with no evidence to back it up?
Woz claims it's repeatable. So why not buy a cheap camcorder, get a friend to be the passenger/cameraman, go record an instance of it actually happening and put it on YouTube? It would be on every news channel in the country the next day and Toyota would be forced to respond directly.
In fact, if I had the kind of money Woz did and thought there was a real danger here, I'd just buy a camera that installed in the headliner and recorded everything that was happening while the car was on at all times, so that I could easily catch the bug when it occurred.