A hit and run can be an accident and one person doesn't stay at the scene of the accident. There is nothing to stipulate that all hit and runs are not accidents. There could be reasons outside of the act of driving that the driver wouldn't want to stay around ( for instance, possession of drugs or illegal items, warrants for arrest, problems with citizenship and legal entry in the US e.g. illegal aliens and so on).
The point was that there is no way of knowing it was "still" a hospital when allied forces are claiming they are taking fire from the building. Just like there is no way of knowing that city hall still has all the politicians in it when it's used as a fire base for the invading enemy.
So the docs without borders who put themselves at risk by being on the front lines contacted someone in the military. A Taliban operative could have done the same so it needed to be verified but more importantly, communication is not instantaneous in that process. There is no one person you can call who has a magic button that will stop the bombing of a certain building or area. Whoever they reported it to had to pass it through the chain of command until it eventually was verified and filtered to those taking actions. A half hour seems quite expedient if you think about the logistics involved.
This is why we need our own boots on the ground. Pretending to be someone else air force ends up with the US getting blamed for mistakes and misdeeds that the foreign forces should be accountable for. In all these threads I've seem America bashing and little to no mention of the Afghans who called the air strike in. If BP oil tells a contractor to cut corners and dump chemicals illegally or even use sub standard parts causing an oil spill, we blame BP oil. The US is basically the contractor here.