The decision is not yours, not ours. It's the parent's. Like everything else about the daily life of the kid. That argument contains no value. Of course there are reasons that one might not do that. Loop/Recur to line 1.
there's a middle ground between the state as inflexible guardian and complete parental sovereignty.
The state has laws and agencies to interfere and check (Disclaimer: I've no clue about the US of A here, but I assume it's not too far off from what I know). But that's not related to the action(s) we discuss. Are we missing a part of the picture? Certainly. Is the partial picture scary? Yes.
The adversaries in the story didn't act to protect the kid. They acted in a completely crazy fashion. There's so many things wrong with this story, I cannot even begin to imagine how someone would defend the side of the cops here..
One (out of far too many) questions: If this mother is utterly incapable, if a lawyer actually can make the point that she might lose her kid if she's not complying: Why does it take 10 month to proceed? I'd say that someone with a little ambition can kill a kid in less time than that...
There's not One. Single. Point. in that article that makes sense, on the side of law enforcement. Zero. The only potential reason to discuss why this might not be so far removed from reality that everyone involved should be ordered to take a drug test is that the article might be lying. If that is not the case ... there is no case.
I've said repeatedly that I don't think there was any point in bringing a prosecution. since you don't live in the US maybe you don't appreciate that the police and the public prosecutor are completely separate entities. The police didn't do anything abnormal in this case.
I don't live in the US, but I often get the impression that in the US, they're less separate than in other countries.
Leaving a child in a locked car is a bad idea, even when it's totally safe, and even with a window cracked. (In fact, leaving a car window open when you're not there is also a bad idea, though a few minutes probably won't hurt.) Honestly, in that situation, it's better to leave the car door open, so the child can get out when necessary. If you don't trust the child to make that decision, don't leave it alone.
If the mother (to stay with the original article) would've fallen unconscious or dead in the supermarket, nevermind that both options would have some consequences for the family, the kid would've been fine.
Calling the cops was fine. Creepy the way it was described, but okay.
Cops arriving was fine. That's their job.
"Huh? The "abandoned" kid is gone already? Let's trace the car and take out our frustration on .. the mother?" wasn't fine. That was just braindead. The correct movie quote variation would've been "Nothing happened, move along".
Theoretical "But here's how the kid could've died" arguments are .. weird. And countless.