I call BS on that. There is no such thing as "disproportionate" in war. You go in to kill your enemy. That's like stating the amphibious invasions of Normandy and Iwo Jima were "disproportionate" because the Army/Navy/Marines had battleships/cruisers/destroyers doing artillery support and had more troops/tanks than the Germans/Japanese defenders had.
BTW....a LOT of French civilians were killed at Normandy.
One death is too many, you do what ever it takes to stay alive, that often means killing the enemy. They can die or give up but when you agree to let a like amount of your soldiers to die just to keep things even you're stupid. You should just give up if that is what you want.
It is Hamas that is killing, why don't they get bad PR?