There are many dozens of eyewitness accounts of Israelis actually being on site and observing the massacre close at hand

Yes there are.
There are also eye witness accounts (by nurses) of Israelis throwing dozens of bodies off the MV Marmara, but it was lies.
There are also eye witness accounts of the Jenin massacre, and that was all lies.
Enemies of Israel lie against Israel.
Do not be so gullible and naive.

You chose to mention the "Jewish American nurse."
Her account does not support any of those claims, and nor does Robert Fisk's first report.