Palestinian militants armed with machine-guns and rocket-propelled grenades opened fire on the rescuers, as Israel called in heavy strikes from land and air to cover their evacuation to the coast. “A lot of fire was around us,” Hagari said.
It was this bombardment that appears to have killed and wounded so many Palestinians.
Funny you mention that. Israeli brain surgeons saved Yahya Sinwar's life by removing a tumor when he was imprisoned in Israel for torture and murder of several Palestinians and Israelis. He "thanked" the lead surgeon by having his grandson abducted on October 7.
[Not defending Israel] As a rule of thumb, I wouldn't trust the word of an interested party in accusing the other party.
Maybe they had 7 hostages and Israel killed 3, or maybe Israel released 4 and Hamas killed the rest, or maybe those 3 were killed earlier for whatever reason, or anything in between.