the premise of the article is dumb
basically, papers studying whether smoking bans work have a hard time establishing causality because people have heart attacks for lots of reasons, like being old or fat or having a genetic predisposition, and not just for smoking or being around smokers a lot
it's only one reason why epidemiological studies are hard to do well, and why basic research is almost always better
but the primary thrust of the slate article is that the science has changed since the oft-quoted helena study
and yea, it would have been dumb to make nationwide policy based on a tiny sample size in montana with data that wasn't good to begin with, but that's not what happened, and if the suggestion is that we should rethink whether we should expose ourselves to secondhand smoke, uh, no