It might seem that way, given that Eichmann is the only person ever to be judicially executed in Israel. But how about the case of John Demjanjuk, aka "Ivan the Terrible"? He was extradited from the US to Israel to stand trial for war crimes (being a Nazi guard at Treblinka) and was sentenced to death in Israel in 1988. However, before the sentence could be carried out, the fall of the Soviet Union resulted in the release of new evidence that showed that Ivan the Terrible was not John Demjanjuk.