@AeropsaceEngr, respectfully, I disagree. If What Mr. Barr did was merely "postulating a combination of multiple failures," Toyota hasn't actually proven that the sticky pedals or floor mat actually occrred in the real world, either.
But I digress.
You may want to read what B. Benjaminson wrote here in a separate thread:
Mr Barr did not "prove" that the truly fatal flaw that "caused" unintended acceleration in the affected Toyotas lay in the software that had been designed into the vehicles' computer systems. He postulated a diabolical combination of multiple failures that could possibly cause unintended acceleration. There is no data indicating that those failures have actually occurred in the real world.