Just recently, multiple Hamas officials have appeared in interviews on the BBC and other channels and denied killing any civilians. It was not even risible.
One IDF incident that stayed with me was the 2006 cross-border raid by Hezbollah which marked the start of the 2006 Lebanon War. There was a lot made of two captured Israeli soldiers, whom Peres and Olmert assured their families (and the public) were alive and well, even though it was known from the start that they were killed during the initial raid (the Wikipedia article mentions that this information, or at least the fact they sustained critical RPG and bullet injuries, was included in classified reports).
At any rate, my point was merely that, beyond the normal fog of war, for PR purposes nobody is going to admit they blew up a hospital, deliberately or otherwise.