"Hamas is constantly hiding among civilians, in schools and hospitals and nurseries"

There is no way you can disprove that. I see these videos released by Hamas, filming armed IDF soldiers in windows of buildings before shooting them or firing an RPG rocket at them. You can see the weapons they're holding

Which makes me wonder. Why hasn't Israel ever filmed one armed Hamas militant in the window of a school or hospital before bombing it?

Is it just hard to film something like this during a war? Nope. Hamas does it every other day, with their smartphones in those red triangle videos. So I would think Israel would be able to film it as well, especially since the PR and global perspective of this war, demands this footage so much. Think of the PR shift if Israel consistently released videos like this. Showing the world, Hamas militants in the window of a school or hospital before it got bombed. The public outrage would be cut in half. So why not do it, if Hamas can do it every day?