Scenario 1: Israel states that the use of the extra powerful weaponry was unintended and did not know there were that many people in and around the building.
There is a man aiming his gun in your general direction. He has fired several times killing those around you. You are pointing a gun at him, but he continues to shoot. You fire the gun, unaware of the bomb attached to his chest. The bomb kills the perpetrator and a innocents around him.

Scenario 2: Israelis knew that there would be casualties, but it was unavoidable.
There is a man aiming his gun in your general direction. He has fired several times killing those around you. You are pointing a gun at him, but he continues to shoot. In front of him is an innocent hostage. You only have one round in your gun, and if you try to shoot around the hostage the perpetrator will escape. Your gun is powerful enough that you could shoot straight through the hostage and kill him. The longer you consider it, the more times his gun goes off. You take a deep breathe and fire your powerful gun, immediately killing the hostage and perpetrator.

Scenario 3: Opponents of Israel state that the extra powerful weaponry was intended and they showed callous disregard for the lives of surrounding victims.
There is a man aiming his gun in your general direction. He has fired several times killing those around you. Two years ago you offered him nearly everything he wanted and he responded by opening fire. One by one, you watch your friends die. In a fit of anger, you pick up the most powerful weapon you have and blow him to bits, to hell with the rest.

What do these three scenarios have in common?

They begin with a perpetrator, aiming a gun, killing several of your people. He was surrounded by people and the death of those around him or those around you was inevitable.

That's all I have to say about the tragedy in Gaza.