I think there’s a lot more than power steering that that could be interfered with. I suspect, although I don’t know for sure, that if you could hack into a car’s computer system you could probably cut out the brakes, except for the mechanical hand-brake, and I’m not sure if even that is entirely mechanical these days.
And you could probably mess with the steering. And I suspect put it on full acceleration.
None of those are normal processes, but if you have a computer involved in mechanical processes, between the cup and the lip as it were, then almost anything might be done by a really knowledgeable hacker. And, if necessary, they could send someone to crawl under the car the night before and make a few extra connections. Stuff that wouldn’t be too noticeable after the car had been wrecked.
It is amazing how quick he was out there spraying water on the fire.