the US pretty much immediately paid compensation to the families of deceased civilians. Along with President Obama calling MSF to apologize, I think that says a lot. Long before the ongoing investigation will reach an official conclusion. A conclusion we (in our lifetime) will most likely never know in, because no one would be insane enough to disclose details about RoE.
A few more details emerged, the US Special Forces and the JTAC on the ground who called in the strike were apparently new to the area. So was the AC-130 crew. I'm a conspiracy theorist (that's what Pprune is for), and I still suspect Afghan forces had some grief against that hospital (like, they were giving medical treatment to taliban combatants), and someone in the US chain of command, in a HQ far away failed to notice this was a hospital. I'd also assume because Afghan forces had called for the strike, it would need to be approved slightly higher up the chain of command than if US forces were under attack (even if RoE are different for AC-130 with their highly capable sensors and direct fire capability). I do wish - at the very least - that the career of that individual has ended. I'm sorry, looking at the satellite imagery, and publicly available maps, this doesn't look excusable to me. Fog of war, battle plans that fail, sure, but you need to draw a line somewhere, and I think it was crossed here. Accountability and responsibility shouldn't be empty words.