No. They absolutely did not have to produce a life threatening event. They could have done it 5MPH and car manufacturers would still take notice because it would still spread like wildfire on the Internet. What they did was supremely irresponsible and the cops should have been called.
They already did do it at slower speeds in parking lots. Manufacturers didn't care. They probably still won't care, which means that it's a matter of time before someone even less morally-bound decides to wreak havoc on traffic.
