My armchair analysis here is that behaving in a reasonable fashion would not result in being able to obtain and exercise more power.

The desire for more power, and thus funding, and thus better career aspirations is as relevant to CPS as it is the local PD.

Of all the spilled ink on the topic of how this stuff happens, there seems to be a culture of, "We lock up the bad guys and throw away the key". It doesn't take much to put you into the "Bad Guy" territory, and once you're there, you're not a person, a mother, a son or spouse with a life all your own. You're a threat to the societal order (no longer a human being), and deserve the full weight of punishment regardless of its implications.

The police departments which manage to actually take high crime areas, and turn them around into lower crime areas despite widespread poverty have undertaken a paradigm shift from, "Putting away bad guys" to "Building a community". Getting to know the community, its problems, its major players and learning what their struggles are and trying to find a way to integrate into solving those problems, using law enforcement as a tool and not its own pursuit.

I suspect child services / social workers are punished far more severely for false negatives than false positives. I think it is safe to say the outrage of failing to save a child would outweigh the embarrassment of a false positive such as this. I could easily see major news outlets and local politicians raising hell for failing to stop abuse but raising far less hell for something like this.

I have had multiple experiences with multiple CPS departments through multiple friends and family members. CPS hardly ever does anything and are largely useless. The only time they did anything was when the police opened up a second investigation because of the problems, and they told them "Don't talk to CPS talk to the cops and have them talk to CPS".

Assume the default for these kinds of agencies is false negatives.

No one wants to be the weak link that gets their name blasted in newspapers when a kid gets harmed. Not that it would really be their fault, but the incentives are obvious to "play it safe".

I feel like "playing it safe" could have been accomplished with the officers just dropping the kid back off back home. I don't see why it would escalate to pressing charges.

2 months later when something happens to the kid this entire thing will get replayed in the media and everyone that didn't do anything will be made out to be a villain.