Potential MMJ patients incarcerated before laws are passed

I've been unable to find information for this type of scenario, was hoping someone would know what happens.

A person has chronic pain and medical grade cannabis gives them the best relief. The person lives in a state that has no medical laws yet but soon will, and will totally qualify for getting a license once the laws have been passed. But before that happens, the person gets busted for growing half-dozen plants and posession of at least 1/4 pound. They get sentenced to jail, about 1 to 6 years.

While in jail, the laws are passed.

Now, would that person be able to get a special parole hearing to be released so they can legally obtain a license and continue growing and smoking for their personal medical use? Maybe their lawyer could get a doctor to come and evaluate them to give a recommendation for medical cannabis? If they can get out that way, will the charges stay on their permanent record?

Or will that person have to endure the remainder of the sentence, or until regular parole comes up?

If he's already sentenced there's not much you can do. If he's still awaiting trial it will all depend on your states mandatory minimums and how nice the judge is. Growing 1 plant is a felony here in washington, but I've seen judges cut people a lot of slack if you can go get your MMJ authorization and bring it to court.