The accused was stopped by police after passing several vehicles at a high rate of speed and was found to be impaired by marihuana.
Police also discovered 18 grams of marihuana, for which the accused held a valid medical prescription.
The Crown argued that lawful possession became unlawful once the drug was used in the commission of impaired driving.
The court rejected this argument, distinguishing precedent on innocent possession becoming unlawful and holding that possession remained lawful because the substance had been validly prescribed and obtained.
As the admitted facts did not disclose the offence of unlawful possession under the Controlled Drugs and Substances Act, the guilty plea on that charge was struck.