"There were many countries that supported [the report and a vote] ... it could have been adopted, but I think that an opportunity was missed and it may not come back."
Mahmoud Abbas, the Palestinian president, under pressure from the PA's executive council and the central committee of his Fatah party, has launched an investigation into the delay.
But there appears to be no respite for him from the barrage of criticism from Palestinians.
A senior member of Hamas has demanded that Abbas resign for supporting the postponement of the vote.
Mahmoud al-Zahar told Al Jazeera on Monday that Abbas was guilty of "a very big crime against the Palestinian people" over the PA's support to defer endorsing the report.
"He is encouraging the Israeli military leaders to attack Gaza, to kill Hamas, and to kill people because they voted for Hamas; to postpone a very important report concerning the Israelis committing crimes against human beings," al-Zahar said.
"He should resign and he should seek a fair trial. He is not representing any of the Palestinian people."
The comments came as hundreds of people in the West Bank city of Ramallah protested against the delay in the vote on the report by Richard Goldstone, a former South African judge.
Protesters waved placards at Monday's events, saying the delay "insults the blood of the martyrs and wounds our people".
Protests were also held in Jerusalem, where pro-Palestinian activists demanded an apology from Abbas.
"If the government had anything to do with the decision we want it to resign," Muhammad Jadallah, the head of the Coalition for Jerusalem, said.
Thirty-two Palestinian groups in Europe also called on Abbas to immediately step down from office.
In a statement, the groups said "the step to delay the endorsement was not less dangerous than the atrocities committed by the Israeli occupation in Gaza".