Is it possible to evaluate the California Medical Marijuana Experiment?

Eric Sterling does some interesting musing and wandering in Medical Marijuana in California — Questions

I am intellectually satisfied that marijuana has a wide range of medical values. […]
Therefore I believe marijuana should be available to patients who need it. So how do I understand what is happening in California? […]
There is a large experiment underway in California yet there probably is no consensus on what the experiment actually is about. Is it an experiment in medical marijuana? Or is it an experiment as Joel Stein says, in legalized marijuana for adults over 18. Certainly it will be hard to evaluate because the experiment is not being controlled or designed.
There are important questions: What is the actual role of the physicians who are issuing the recommendations? Are they facilitating the proper treatment of serious medical conditions that have been resistant to conventional medical treatment? Are they serving to block improper juvenile use of marijuana? Does their “gatekeeper” role help mitigate the abuse of marijuana?
It is time to ask the academic world to step forward to begin to seriously evaluate this experiment.

I understand the questions, but disagree with the final conclusion.
It must be disconcerting for those who spent so much time and effort developing and fighting for medical marijuana in California to be successful, and yet at the same time be unable to even identify their baby.
As a pure scientific medical venture, California’s medical marijuana movement was hopelessly doomed. The federal government’s unjustified active opposition insured that the valuable “state laboratory” concept (as envisioned by Justice Brandeis) could not function. Therefore California’s medical marijuana “system” is a political/social chimera, not a scientifically controlled experiment.
Asking some in the academic world to put something that chaotic into a clinically analyzed box could be disastrous. Lacking rigidly defined controls, the science will be seen to be undefinable, therefore failed, when in fact it is the public policy that has failed the science.
Imagine any other scientific experiment where the very ability to control the environment of the experiment was denied the experimenter — where testing of new food crops, for example, had to be done à la Johnny Appleseed. It would be very hard to be sure of the purity of your results, and yet there would still be something to learn (and enjoy) from each apple tree, until the day that the world woke up and allowed controlled tree farms to develop the best apples.
Medical marijuana in California is a cruelly grafted beast, yet is something to be treasured for whatever combination of things it has managed to be, until the government is willing to allow it to become something more controlled and measurable.