Israel is claiming that some rockets launched by Hamas towards Israel went off course and hit the hospital.
I remember Russia staging a "Ukrainian missle attack", but they were so bad at it that the damage was on the side of buildings facing away from Ukraine. Should be pretty easy to check that here too...
The whistle tells you the direction the rocket came from relative to the position of the camera. We know the rocket had to pass over the camera position before striking the hospital, and from that you can extrapolate where it came from.
None of the videos purporting to show a misfired rocket align with the one verified video showing the strike. The video posted by idf of what they claim is the rocket barrage responsible for hitting the hospital was shown to have been taken after the hospital strike (and has since been removed from their post).
There is a lot of finger pointing and blame going on right now. I'm less inclined to believe the side misrepresenting evidence, but neither side can be trusted on their word alone. This means we need evidence, which is in short supply at the moment.