Of course it could have happened. You don't even need targeting for this to happen. You can drop bombs at random and kill whoever is unlucky enough to be in the wrong place. The US has a long history of doing it (Japan, Vietnam, ...).

So yeah, the military and whoever decided that a war was a good idea are to blame.

People working at Palantir are as much responsible for the killing of these 123 children than seatbelt manufacturers are responsible for the people who died because their product failed. That is, because they didn't do their job correctly, people died, definitely worth feeling bad about. However, should people stop working in seatbelt manufacturing because of it? Absolutely not, we need seatbelts, because without them, things would be worse.

Palantir, or whoever does target identification, is like the seatbelt of the reckless drivers of the militaries, who, for the lack of precise information, would just carpet bomb the place. It is not a hypothetical, it is how the US has worked before they had precision ammunition.

This is essentially a trolley problem. The war is the trolley, people who work for Palantir are the ones pulling levers. And if there is no one to pull the lever, the trolley is gong on a track with a lot of people on it.