The film doesn't go into much detail. I firmly believe that the issue is that you cannot decide on behalf of an addict that he/she needs to get clean. It is a decision they have to reach on their own. Therein lies the crux. What gets an addict to that point where they will seek treatment and become committed to recovery? If there are no consequences to their addiction, their motivation will be low. If on the other hand they are spiraling lower and lower (reaching bottom), they may decide that addiction is not worth it anymore.
My only addiction was nicotine, but I know I tried to give up a couple of times because of other people nagging, but I always started again. It was only once I decided that I was tired of the smell on my clothes, the taste in my mouth, the cost, the inconvenience etc. that I gave up and then it wasn't hard at all.
What the doctor in the documentary may miss, is that if you drag an addict off to rehab or treatment without them wanting to get clean, the chances are that they will get sober for a short while but I think the relapse rate will be much higher. If they want to truly get clean I think there is a better chance.