Eh, trying to post-hoc justify your actions is fairly human in general...
... that said, there's post-hoc justification and then there's whatever the blazes that was. What made me boggle at that statement the most was the "Want child safe, must put bullets into vehicle" bit. Like, what the ever loving hell leads someone to thinking the best way to alleviate that danger is to fire bullets in the kid's general direction? Escalate to firing at all? Did this guy not know about goddamn ricochet, just to start? Misfire, chance of the other person having a gun, any of the things that could have caused? Just watching folks drive, I know we fail our countryfolk at teaching physics pretty hard, but th'hell are we paying these chucklefucks for if they can't even manage the basic shooting safety I've seen taught to goddamn twelve year olds?
I'unno if that's worth two bads, but a single one... maybe. Gods know if our justice system wasn't quite so screwed up when it comes to cops that would be something like criminal negligence and some level of manslaughter at minimum. Though I guess at least we're apparently not paying him anymore, at least for the time being. Who knows if he'll be rehired, either in the same area once the news dies down or a different precinct.
Also, it wasn't even pot when it came to that second-hand thing. How many tobacco smokers have kids, again? Apparently it indicates such a reckless disregard for human life to justify shooting first. I guess it's another reason to quit...?