From my experience in insurance, this pattern makes a lot of sense as applied to houses - one house can be burned to nothing and the house next door totally fine, mostly depending on roof type and proximity to combustible material (eg landscaping plants). Whether or not burning embers will catch your house on fire matters a lot more than some notion of how 'big' the fire area is.

I don't know how much flammable material cars have but I've heard claims there's a lot of combustible plastic in the engine area. If that's true it might just be a crapshoot of whether burning debris lands on your car (or lands in an area where the fire can spread to flammable material in the car).

I think there's plenty to criticize the government for even in the official story:

Electricity monopoly leading to poor management of power lines

Water monopoly leading to denial of water for firefighting

Poor emergency response leading to failure to warn residents

Cops putting up road blocks to stop people from fleeing

I'm inclined to think DEW is to pull attention away from the admitted and obvious failures.