I just did a quick perusal of the RCW (9.41.040) and there doesn't appear to be anything in STATE law that bars an un-convicted drug user from owning or possessing weapons.
The issue here is FEDERAL law and the restriction on FFL dealers in selling to someone with a history of drug use.
If he answered "NO" to question 12 e (Are you an unlawful user of, or addicted to, marijuana, or any depressant, stimulant, or narcotic drug, or any other controlled substance?)
of the 4473's he filled out while attempting to buy those new guns, he could be subject to prosecution on felony charges.
I am sure his argument is that he is not an "unlawful
" user because state law allows it, but I seem to remember pretty clearly when CA first allowed MM, and then when we did it, the whole State vs. Feds issue coming up. If he is in the business of taking advantage of these laws for profit you would think he knows about the Federal stance. Pretty silly argument that you were thinking about state law when filling out a federal form.
Interesting catch 22 when the Feds continue to list marijuana as a controlled substance without any legitimate medical use and states decide to allow "medical" use. Is it right or fair? I don't know, but the law is the law.
Knowledge is power.
My suggestion would be the more he whines and gets attention, the less sympathy he is going to get. Sounds like he is facing charges under state law for being a little fast and loose with the rules. Maybe he should just shut up and find someone to do a private sale. I imagine he has made enough coin selling weed that he can afford it...