"I don't think they envisaged having to write a law for an army who pretend to refugees that they are also refugees before bombing their camp, so no, this exact situation isn't in the law. Because it's so far from accepted norms the law doesn't exist.
But you can infer that if it's prohibited against combatants it's also prohibited against civilians if you go on to bomb them and kill hundreds as part of that "operation"/massacre."
No.
The IDF operatives only pretended to be refugees in order to enter Nuseirat undetected and to make their way to a building near the hostages in order to prepare for the mission undetected.
As soon as the mission started by advancing on both buildings simultaneously where the hostages were kept, the IDF operatives were no longer pretending to be refugees.
Indeed, nobody could mistake them for refugees given the fact their weapons would have been very much on show and visible.
That means it doesn't constitute an act of perfidy.
The article you linked to states:
"The rescue of Argamani seems to have gone smoothly, while the team extracting the three other hostages ran into trouble.
Chief Inspector Arnon Zamora, an officer in an elite police commando unit, was mortally wounded during the break-in, in which all the Hamas guards were killed, Amos Harel, a veteran defense correspondent, wrote in Israel’s Haaretz newspaper. Then the rescue vehicle carrying the three hostages got stuck in the camp, he said.
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."
Important, crucial information underlined.
The IDF operatives were close to getting away from Nuseirat with the hostages almost undetected. But, unfortunately, their vehicle got stuck.
Hamas terrorists then start attacking the prone vehicle with soldiers and hostages inside with machine-guns and rocket-propelled grenades aka RPGs.
Due to this, it is allowed to call for supporting fire including air strikes. That includes striking areas where Hamas terrorists and civilians engaged in hostilities were firing RPGs at the vehicle as well helicopters.
It's permissible to allow a fire corridor to be created too. That's how you get hostages from busy Nuseirat all the way to the beach to be rescued by a waiting helicopter.
It was the actions of Hamas that endangered the lives of civilians and their heavy fire would have resulted in a lot of civilian deaths. If they hadn't done that, there would not have been the need to have airstrikes to take Hamas terrorists out too.
Hamas used really heavy, excessive weaponry in a densely populated civilian area. That led to more civilian deaths.
Had the vehicle not got stuck, the IDF operatives would have been well away from the crowded Nuseirat. Its better for the soldiers and hostages to be away from that area as quickly as possible due to the very high risk of ambush by Hamas in addition to the extraction team being overwhelmed by Hamas' numerical advantage in Nuseirat.
As I said before, the mission was NOT intended to kill, capture or injure the adversary. Absolutely not with a small team in a heavily populated area with loads of Hamas terrorists there.
No, the mission intention was to rescue the hostages as quickly as possible with Absolutely NO time wasted for any reason.
Unfortunately, things usually go wrong in military operations. And that was the getaway vehicle getting stuck.
This operation doesn't fit with claims of perfidy at all.