I live in a medical marijuana state that also now lets you have non-medical marijuana. I do not use marijuana.
It is my opinion that medical marijuana has a place in treatment for certain issues.
It is also my opinion that if you are prescribed this by a legitimate physician for a legitimate reason and you use it as prescribed, than you have not relapsed.
If you are completely honest with yourself, deep down honest with yourself, you will know whether you are using this as an excuse and whether it constitutes a relapse or not.