Mahmoud Abbas, in a speech at the American University today, accused Hamas leaders of escaping Gaza in ambulances and hiding in the Sinai during Operation Cast Lead, according to Palestine Press Agency.
Abbas also said that the PA warned Hamas in Gaza a week before the operation that Israel was serious and that Hamas should extend the truce, and that Hamas ignored these warnings. Abbas says he then appealed to Hamas leadership in Damascus and was similarly rebuffed.
During the war there were a number of reports that at least one Hamas leader, Mahmoud al-Zahar, had escaped to Egypt via an ambulance. Even two weeks after the war people were wondering where he had disappeared to.
The Goldstone Report, not very convincingly, says it found no evidence that Hamas used ambulances illegally during the war.