I understand the Chinese embassy flattened by Clinton during his Sarajevo bombing campaign was a source of constant radio traffic.
If we had electronic emission signatures we would surely learned that Israel bombed the forward UN post because it was providing either C&C or foward observer data.
It is possible that it was a less noticeable contribution: that they simply were allowing terrorists to hide behind the UN label.
After all the terrorists are using red crosses on vehicles, hiding in schools and hospitals, and fighting in civilian clothing. They certainly would hide at a UN "safe" area.
And the UN guys would have known it.
Israel sent a massive message to others who would try the same.
that's why Israel hit an ambulance. Palestinians use ambulances to move around their senior people and weapons.
Intel proably indicated a senior Hezzie like Nassrallah might be inside.