"Is this similar to the lack of consequences for folks who willfully smoke around children?"
So, let me get this straight. Cigarettes are causing all this bad behavior in kids?
Gee, who woulda thunk it. There are less smokers now than in 1950.
"all?"
Sounds like sloppy reading, to me.
I don't recall anything in the study that asserted that the smoke related poisons found in the blood--higher levels of poison correlating with higher levels of misbehavior--were 100% responsible and the only responsible factor for the misbehaviors.
It is clear from the study that the smoke related poison(s) are A SIGNIFICANT FACTOR in the misbehaviors. This study did not have anything to do with apportioning out percentages for each contributing factor to misbehavior.
But I suspect you knew that . . . if you thought about it, at all.