Something can be both a “terrible mistake” and also a violation of international law.
At a high level, it seems unlikely that American military leaders would intend to bomb a hospital, considering the horrible human toll and subsequent political and public relations disaster.
Perhaps the investigation will turn up a more complete story about why the hospital was targeted.
If it is true that some of our “allies” on the ground in Afghanistan directed the US military to bomb that location, as was reported somewhere I read, then that is no excuse for such a colossal fuckup – especially considering that the MSF had previously told all sides the hospital’s coordinates – and whoever in the US military took that information at face value should take proper responsibility, and whoever directed them should also be dealt with.
If instead it was, as themgt speculates, a deliberate choice by someone in the American military to target the building with full knowledge that it is a hospital, then that person should be tried for war crimes.
perhaps we didn't create Al-Queda: https://www.youtube.com/watch?v=WnLvzV9xAHA [Hillary Clinton]
perhaps we're not involved in training/funding ISIS: https://www.youtube.com/watch?v=FxDKmM8npBQ [John McCain]
or maybe there's something seriously wrong with the traditional narrative - http://naplay.it/763/41-47
while I'm not 100% sure about that (it seems unthinkable for a human being, but people's judgement can get pretty out of whack in wrong environment), let's assume for the sake of argument that your military leaders are sane.
even then, all it requires is the bare minimum of military leader people closing their eyes for just long enough.
and if you believe they wouldn't do that intentionally, then we'll disagree about that. you don't get that position without the ability to look the other way with laser-sharp focus. it's part of the job (and it's disgusting).
but they would say "you don't know what it's like". meditate on that for a bit. this world, huh?