[Nifster]

That and the inability to handle a vehicle while so impaired

[NobleFree]

Drivers who had too little sleep have died; would it be accurate to say they died from too little sleep?

That and the inability to handle a vehicle while so impaired

So by the same token, someone who gets stoned, drives, and dies in a crash did not "die from pot" but from pot-and-the inability to handle a vehicle while so impaired.