Once again, that word "civilian". "Civilian" is defined by usage, not by original intent. And many of the apartment buildings that collapsed were because their foundations failed from the collapse of Hamas tunnels. Standard construction techniques are extremely vulnerable to damage from being undermined. Look at the pictures of the devastation--earlier on you could see the lines. Since then it has become far more blurred as Hamas tends to occupy or booby-trap just about everything.

And it's not a thin pretext--every hospital is a Hamas base. Remember all the rejection of the idea that Hamas HQ was in bunkers under the main hospital? Repeated denials that any such bunkers existed. Israel had a very simple response: we built the bunkers, we know they exist. If hospitals were acting as they should be they would be open territory--the IDF could simply walk in and look around. Yet every time it's been a big fight. And I remember a supposed "hospital" strike where they actually hit a tunnel--got the commander they were after and got secondaries. A bomb that simply explodes underground isn't going to cause secondaries, so clearly they hit a tunnel that supposedly did not exist.