Jim,
"No. I raised it as an example of how Israel's enemies lie."
No you didn't - you were caught out in a hilarious porkie which I shall be chuckling about for some time to come

No. I raised it as an example of how Israel's enemies lie, along with the example of the Marmara. The exact figures do not matter, only that there was no deliberate killing of civilians or body hiding. They lied about that in both examples, and undoubtedly about Sabra/Shatila too.

Francis Pym slated Israel for their actions at Sabra Shatila

He did not.
"Francis Pym, the British foreign secretary, cleared Israel of blame for the massacres at Sabra and Shatila, two Palestinian refugee camps in Beirut, where, over two days in September 1982, a Lebanese Christian Phalangist militia killed as many as 3,500 people.
Having invaded Lebanon up to Beirut, Israel allied itself with some Christian militias fighting in the Lebanese civil war. During the massacres, the Israeli army had surrounded the camps and fired flares at night to illuminate the dark at the request of the Phalangists.
But Pym, writing an initial assessment in September 1982, said Israel had been guilty only of "incompetence, miscalculation, overeagerness to clear out the remaining PLO and unwise dependence on undisciplined militia".
http://www.thenational.ae/news/world/europe/british-national-archives-releases-classified-government-documents