The decision is no surprise: the Arizona Supreme Court ruled in State of Arizona vs Danny Ray Hardesty that Hardesty, despite being a member of the "Church of Cognizance", a cannabis-worshipping new-ageish sect, cannot eat or smoke cannabis wherever he likes and under whatever circumstances, and denied his A.R.S. § 41-1493.01-based appeal of a criminal sentence for possession with intent to distribute. (The COC self-represents as neo-Zoroastrian, but the connection to the Avesta or Mazdaism is limited to passages about Haoma.)
If nothing else, the case demonstrates why the task of expanding liberty, even very narrow religious liberty, and even narrower still, religious liberty of flakes, is best not left in the hands of flakes. The COC has been around since the early 1990s and had considerable time to file good, clean test cases establishing exemptions for religious use, first in private, then in public, then perhaps while operating a motor vehicle. Even if they waited for the burden-shifting statute's adoption as law, they had a full year to come up with a clean cases to start carving out exemptions. Better still, they could have joined with more established religious groups like the Hindus or even the Rastafarians to start pushing back against the prohibition of their sacrament. If anything demonstrates that there are less intrusive ways for government to pursue its compelling interest in limiting cannabis use per se--and that there is legitimately a compelling interest in protecting individual health is dubious--it is India's experience with legal bhang for both religious and recreational use; use by Rastas is largely illegal but their claims to both sincerity and harmlessness are much stronger thanks to history. (Which leads one to wonder: why hasn't either group raised a religious liberty challenge?)
A.R.S. § 41-1493.01 places the burden of proof on the State of Arizona to show that its policy is the least restrictive means to pursue a compelling interest. Hardesty's appeal by its nature forced the motor vehicle issue. If cannabis use leads necessarily to driver impairment (not clear) then a ban on use while driving is the least restrictive means for the state to pursue what would seem to be a legitimate compelling interest in keeping people from hitting other people with their cars. Think about it. If I claim that my (hypothetical) drunken driving is an expression of my sincere reverence for Bacchus (who's a bad motha-shut-yo'-mouth with whom you do not mess), Judge Pentheus should probably deny my appeal as my conduct infringes too much on the well-being of others.
The astute reader will note that the state prosecuted not for use but for possession. Fair enough. But the point stands: Justice Rebecca White Berch was able to avoid, in her opinion, and justices Ryan, Bales, and McGregor in their concurrence, questions of whether or not there was a less restrictive way for the government to pursue its interest when use in a private home or a religious ceremony are at issue.
That this was a poor choice of test case aside, the opinion itself contains a rather silly line of thought: that a ban could--and they do not take up the question of whether less intrusive policy is available--be justified in pursuit of the state's interest in halting criminal traffic in cannabis. Any criminal traffic is the result of the substance being contraband in the first place; Justice Berch is allowing for the possibility that the state could make something contraband because it is contraband, that the state has a circular, closed-loop compelling interest. There's no more charitable way to describe the argument, and I for one find it at least as dippy as the doctrines of the COC.
A final remark: Suppose that Hardesty were to have prevailed or that a similar but more limited appeal is successful in the future. We'd have a very strange situation on our hands, as faith would excuse one from marijuana prohibition, but reason would still be no defense. (Religious readers, especially Catholics, Buddhists, and Muslims, please note that I'm not making a general statement here about the connection between reason and faith.) If I light up, I couldn't claim as defense that I was doing it for enjoyment, that I'm aware of whatever health tradeoffs are involved, and that I endangered nobody. But I could get the law to leave me alone if I thought smoking a doob put me in better touch with Gitchee Manitou or like, spiritual consciousness, man. For reasons rooted in the U.S.'s early history, religious conduct is privileged in both popular belief and in the law. Yet it would seem--in light of consideration of compelling interest--to be sensible to adopt the following rule of thumb: Anything one is allowed to do in the name of faith, one should generally not be forbid to do. The irrational should not be privileged over the rational.