Should it turn out - in the case of any road / rail collision - that someone was criminally negligent, then - yes - the full weight of the law should be thrown at them. But there isn't always a negligent road driver - I'm sure regulars here will recall at least one incident in the last couple of years where causes turned out to be very different. I also note that there's a contradiction (perhaps just a technical one) even in the reports so far - it's even unclear to me if the train ran into the road vehicle, or the road vehicle ran into the train.
It would appear that the train ran into the road vehicle due to the damage to the front cab of the train.