There does not have to be a conspiracy here (even of silence) but you are correct - if the Woz says there is a software glitch then a software glitch there is.
If the Toyota guys can't find it then - yes - they should ask someone who can find it.
If the Toyota guys can't find it then - yes - they should ask someone who can find it.
I can only hope for a mighty public outcry and backlash against these opaque practices. It's one thing to convert more systems from mechanics to electronics. It's another thing to wrap the entire thing in secrecy and obfuscation. Ralph Nader should be leading the charge on this.
However if he can reproduce this quite easily then there is probably a software bug. And Toyota can't afford a recall. Honestly this just has to be taken to courts, its the driving force of our economy.
It doesn't mean that he is necessarily right, but he is definitely worth paying attention to.