Non-random thought: It wasn't a cyber-attack.
?? Theory ??
Why do I say that? --Because it's the excuse that the press is reporting.
Woth this said, it was proven in like 2014 that cars could be hacked. I think the person that did it to orove it hacked a Jeep grand cherokee. The SUV had throttle by wire and steering by wire. The hack gave them complete control of the vehicle to operate. Roughly 2016 or 17 manufacturers started putting firewalls on ECMs to prevent this. It makes it slightly hard to buy a programmer to change parameters that would boost engine power and things of that nature. Its crazy what can be taken control of remotely nowadays.
"Ways Hackers Can Take Control of Your Car | Reader's Digest" https://www.rd.com/list/ways-hackers-can-take-control-of-your-car/
Article referencing what i mentioned.