Except it’s relevant isn’t it? If Hamas use child soldiers, and they have a tactic of baiting IDF soldiers to chase into ambush, then it’s highly relevant to the IDFs actions.
That the child threw an explosive at the soldiers it doesn’t guarantee they were a member of Hamas (or IJ, or one of the other options) but it does suggest it, doesn’t it?
No one is saying “oh great a child dead”- it’s horrible, and the boys poor parents must be suffering terribly. But that doesn’t mean that the IDF were just sitting on the corner smoking a fag, saw a few kids go by and thought “oh this is a laugh” and took a pot shot.