The issue is; can ingesting marijuana lead to an 'impairment' days later, justifying a 'Driving While Impaired' charge? The 'Driving while impaired charges' were based on their being impaired, not on THC. I think you could say that based on the cases involved. One person's impairment resulted in the death of others, the other person admitted drinking and smoking within the 1/2 hour before being pulled over for irratic driving. Thank goodness they got him before his driving resulted in death as in the other case.
"-- The four judges in the majority bent over backward to reach this bizarre conclusion. ---
--- The three dissenters noted that such a conclusion is contrary to the law's intent (to protect the public from impaired drivers) and inconsistent with state and federal criteria for Schedule I substances (which are supposed to be psychoactive chemicals or precursors to them).
They also argued that the ruling results in an unconstitutionally vague law that invites arbitrary and discriminatory enforcement. --"
We are arguing a constitutional issue.