The UN Relief and Works Agency for Palestine Refugees (UNRWA), an aid agency active in the West Bank and Gaza, had hoped for "a fresh start" in long-strained relations with Israel after the charge was found to have no basis.
"I asked for an apology. I never got one, and I am still waiting for one, although not with bated breath," said UNRWA Commissioner-General Peter Hansen on Monday.
His comments came while he spoke to reporters during a visit to New York to address the 191-nation UN General Assembly.
But instead of apologising, Israeli officials had quickly resumed criticising the agency behind its back, Hansen said.
"I asked for an apology. I never got one, and I am still waiting for one, although not with bated breath"
The initial Israeli accusation, based on blurry black-and-white video footage filmed by an Israeli military drone, was made in early October as Israeli forces carried out an invasion in Gaza against Palestinian rocket attacks targeting Israeli settlements and border towns.
Hansen at the time said the allegation endangered UNRWA staff working in the Palestinian territories by encouraging Israeli troops to think UN vehicles were "transporting terrorists and weapons".
Stretcher, not rocket
A UN investigation concluded that the object identified by Israel as a Palestinian Qassam rocket was in fact a stretcher, a finding Israel did not dispute.
But within days, he heard from other governments - which he did not identify - that the Israeli government was making the rounds with a private briefing spelling out 29 additional
allegations of UNRWA wrongdoing, he said.
UNRWA had responses to all 29 allegations but had never been informed of the charges directly by Israel, he said.
The recent incidents were only the latest in dozens of cases in which Israel levelled charges against his agency that ultimately were found to be without foundation, he said.