I'll definitely admin that I'm interpreting the data to fit their own political/moral views but the conclusion "10 billion on drug incarceration almost pay for themselves through reductions in health care costs and lost productivity" seems that economically the difference in incarcerating addicts and providing them healthcare is negligible.
If the economic difference is negligible then what reason is there for incarceration over providing healthcare? Crime did drop in the 90s but there's also the reality that those with criminal records are predisposed towards recidivism, a complicated issue on its own, but it seems that incarceration leads itself to staying criminal while healthcare at least has less direct links to criminal recidivism.