I’m not sure I understand your question, so if I don’t address it, perhaps we can clarify with some give and take to reach some understanding. And it could be I misunderstood what you were saying in your original post.
The folks in the story are looking for a criminal prosecution. You stated that on a certain set of assumed facts “the person would still be in the wrong and liable civilly and possibly criminally.”
For civil liability, the standard of proof is generally ‘a fair preponderance of the evidence’ - more than 50% of the evidence in your favor to win. For certain cases, not applicable here, the standard is a higher ‘clear and convincing evidence’. And for criminal prosecutions, it is a much higher ‘beyond a reasonable doubt’.
In your post, you might get to the preponderance’ level, with ‘possibly’, you are a long way from clear and convincing proof, much less beyond a reasonable doubt.
So this matter is a long way from a criminal prosecution at this stage.
_____________________________________________________ You don't understand this? Trust me, it's not very complex. Civilly if the driver is found at fault, criminally if the driver was at the time, driving reckless, drunk et al...