In the US you are required to call the police to report to the scene of an accident. It is not always done this way, but you asked what the US laws indicated.

I'm not sure the other guys who have a strong opinion on slandering Chris's memory. I've never thought Chris was high during the moment of the accident, just generally using within that span of days so he would reasonably assume he would test positive as even cocaine stays active in your system for 72 hours.

Chris wasn't "driving" Tony at the time as in chauffeuring him so I'm hard pressed to think he would have been vilified for it.

Had he been found to test positive while driving they likely would have given him a DUI after the fact. It would then be up to the State Prosecutor to proceed or not. And this would largely depend on Chris's cooperation as it related to the drawing of his blood for DNA tests.

Not in every situation but largely in most cases if you have money to fight the case and you refuse your DNA to be taken, you can reasonably expect to have a DUI charge overturned in the US. Without proof from the night of there is little case if any to prove against you. Chris had the $8-15K it costs to effectively defend against a DUI charge. I doubt he would have been charged, seen those charges stick, or do time. He may have gotten his license suspended through all of this somehow but I'm not sure that would really stop him from driving if we're being honest.