If someone is actively fighting from the hospital, it probably loses its protected status, but that's a nitty-gritty international law issue where the conclusion depends entirely on who might be sitting on the ICC at the time, unless a Security Council cares enough to force the issue there and veto it.
A war crime requires intent or willfully ignoring facts (several Imperial Japanese officers attempted to claim that war crimes were conducted without their knowledge). Calling a shitty air strike does not qualify unless it could be shown that someone along the way knew for certain it was a protected location and was not being used for attacks.
To expand a metaphor.
This clearly was a mistake, and when mistakes are made they should be paid for. That's all. The correct posture in response to this isn't ass-covering.
This is what's frustrating to me. That the argument that it was a mistake is expected to mean anything. If I make a mistake that costs my operation at work an extra $50 because I'm overworked and make a typo, I get fucking reamed for it, and many working class people live with daily anxiety over the idea of potentially getting fired over inevitable human errors of minor consequence, with all the serious shit that follows being unemployed. But when someone in a position of serious responsibility fucks up in a way that ruins innocent lives, mistakes seem to be much more easily forgiven and every benefit of doubt granted in determining whether it was a mistake. I can't blame a transposed digit on burnout, pressure, and time restraints and expect sympathy from anyone, but others can empty a clip into someone because they're on edge and that's nothing more than an unfortunate but understandable tragedy...
In a military sense, that is exactly the way things work.
If I manage to break of a bolt when I'm working, the company can fire me, or possibly try to make me pay for it on the basis of an employment contract. If they take me to court over it, my burden of proof to tell them to fuck off is essentially that breaking bolts or making typos is within the reasonable scope of my duties. This applies further, as a defense against outside liability, if that broken bolt was to go flying and hit someone in the eye.
In the military sense, various officers and nco's up and down the chain will have their careers destroyed over this, if anyone could actually find fault (and they probably won't, because it's a pretty clear fog of war affair), they could face court martial with punishments that basically go up as far as you want, depending on charges. In the international sense, it's nothing the ICC could charge without them setting new standards for ICCness, which would be pretty damn impressive. This would, of course, result in the affected countries ignoring the fuck out of them, because offering up scapegoats is not something real countries do to the court of public opinion.
Edit for additional reading point:
https://en.wikipedia.org/wiki/Command_responsibilityShould give you a good idea at how fuzzy the Medina Standard is in general.