Disclaimer: I own a Model S
Of course it's also looking like they should have grounded the fleet after the first crash, given the history of the aircraft prior to its last flight.
It almost seems like a right-to-repair issue, where manufacturers are going out of their way to avoid documenting how their products actually work for fear of losing control over them or of disclosing details that a competitor or patent holder might find useful.
There definitely needs to be a strong regulatory response to that kind of behavior on the manufacturer's part when it comes to safety-critical updates, or even updates that might conceivably impact safety of life. Which, in the airplane business, is basically all of them.