Bigger questions about the political, social and religious landscape of the time, and how this fuelled the toxic atmosphere in which the rally took place, were outside its legal remit, however. Thus, much of the kind of national soul-searching needed to come to terms with what happened, and why, still remains to be done.
"In my mind, they failed to investigate the most important thing, which is the incitement to kill Rabin," says Gitai. "What are the schools of thought which gave the basis for this guy who killed him?" For the firebrand with a reputation for touching on some of his country's most sensitive issues, in films such as Kadosh, Kippur and House, this is not talked about enough at home. "So, in a way, the film itself is the investigation committee which never happened."
He has described Rabin, The Last Day as an explosion, whose splintered structure tries to capture the way that he feels the assassination "explodes certain parameters, or let's say the values, of Israeli society. I didn't have any other choice," he told a reporter, "but to explode even the narrative."
At the centre of the film, anchoring its many parts, are scenes recreating the commission and some of the interviews it conducted, including one with a man whose footage of the assassination and eyewitness testimony throw up more questions than answers. Why, for example, was Amir allowed to stay in a secure area? And why did the cameraman, who sensed danger in the air, mistake him for a plain-clothed policeman?
Gitai was given access to the unpublished protocols of the commission by the (now former) Supreme Court President, Meir Shamgar, ensuring the accuracy of these scenes. "The entire film is really factual," the director says, "because I decided from the beginning that this is too sensitive to be allowed to just be wild [speculation]. So I thought we should stick to the facts. We were also advised by lawyers that checked every detail, so that's the case."
He also wanted to go outside the limits of the commission and look at the elements that helped to create a climate in which the assassination became conceivable. In the frame are rabbis who placed a deadly curse known as a Pulsa Dinura on Rabin; fundamentalist settlers, armed with the Torah and guns; and, notably, Likud's Benjamin Netanyahu.
Archive footage shows the future Prime Minister addressing a crowd in which some people are calling for Rabin's blood, and walking with demonstrators carrying a coffin. How far does Gitai want to implicate Netanyahu?
"I don't think Netanyahu had a programme of killing Rabin," he says. "But I think that they wanted to weaken the Rabin government to destabilise it. For me, the result is that we have now been stuck for 20 years in immobility."
Right-wing Israelis painted Rabin as a "traitor or some sort of lunatic leftist" but Gitai, who travelled with him to Washington and Cairo and interviewed him (some of this appears in the film), disagrees: "He was a patriot but his idea of being a patriot is not necessarily an extremist nationalist. For him, to be an Israeli patriot meant you have to find in-roads and to accommodate the relations of the region. I think this a good road."
One of the problems in the Middle East today, he believes, is that leaders don't want to make such accommodations. As he sees it, this is not unique to the current Israeli government, but a region-wide failing.
"The problem is that the most stable coalition of the Middle East is of people who don't want peace. And they exist on all sides. And they help each other."
When Rabin gave orders for the army to withdraw from Palestinian cities, he says, "it was exactly the moment that the Palestinians, ultra-nationalists, and fundamentalists put the most bombs in Israeli civil centres, which reinforced the Israeli right and extreme right.
"The guy who finally killed Rabin is Israeli right wing but the fact that the Palestinians helped to discredit the Rabin government contributed to it."
The film ends on a despairing note, with one of the Shamgar commission magistrates walking out into a rain-soaked street lined with Netanyahu posters. But would things really be different now if Rabin had survived?
Probably, because he offered a way of looking at his neighbours that sought to embrace the other. We will never know the extent to which he'd have been able to put this into action and how much it would have achieved, but Gitai is in no doubt that it is the way forward.
"Peace is like a relationship, an intimate relationship, and you cannot do it unilaterally."
Rabin offered to support the Palestinians, not just cut them loose. He would pay the salaries of 24,000 workers, he said, and supply water and electricity.
"This is the way to make peace," Gitai suggests. "And this is very different from what we see now, where each group is caring only about themselves. I'm not only talking about Israelis. I am talking about the entire Middle East. And we need to show this other face. I think a figure like Rabin symbolises some kind of openness."
