Just in case you didn’t follow the link
This article is from Reuters which is considered a credible source.
The report was compiled by UNWRA so it was investigating itself so potential for being less than objective in that respect.
However UNWRA will be passing on the report to external agencies specialising in human rights abuses.
They have eye witness accounts that tally with eye witness accounts gathered by other sources. Reuters also intimates that UNWRA have forensic evidence of physical assault.
The UNWRA report is not in itself in the public domain but UNWRA seems to have a portfolio of fairly robust evidence to support their claims of “had experienced included severe physical beatings, waterboarding, and threats of harm to family members.”
Furthermore, we see today that the President of Ireland, who has top level access, has issued a statement that includes the following
” The releasing of a propaganda campaign against the United Nations is a scandalous travesty against the little less than heroic efforts of all those involved on the frontline in Gaza - medical staff, those working to supply nutrition and aid in the most trying of circumstances, and those other dedicated professionals in UNRWA who have lost more than 160 of their colleagues."