I read the GP post as suggesting an actual crime likely occurred. You, I, and many others (especially people who tend to use HN) don't consider drug use an actual crime. Judges sometimes sentence (actual) criminals to drug rehab programs as an alternative to jail for certain things, e.g. if perhaps someone burglarized homes to fund a drug addiction.
I have no idea, though. It would've been better if they gave a little more detail about the nature of the crime.
Sure, that's possible. But, even if it were some sort of other crime that was exacerbated or precipitated by a drug addiction, the fact that the sentence included the option of rehab + probation seriously limits the badness of that crime.
If this were the scenario, and I had to guess, I would say it probably was some sort of property crime. People other than the perpetrator tend not to get seriously (physically) injured in most property crimes, and insurance often covers the damages. In any case, monetary restitution to cover the damage plus rehab. should be a sufficient sentence.
I have no idea, though. It would've been better if they gave a little more detail about the nature of the crime.