"Yet the mystery remains: a distinguished soldier with no proclivity for suicide, without leaving a note, standing at a vantage point with a long-range rifle n line of sight of the VIPs, should at the absolutely most ideal moment for an assassination at once shoot himself in the head with a rifle and somehow find a way to fall off the roof? What an odd simultaneous set of coincidences!"
We have two additional pieces of evidence to consider. First, the clumsy way in which the Official Story was produced indicates that this wasn't an official Israeli government operation. Had this been a government operation, we can expect that a plausible Official Story would have been immediately at hand for each eventuality. Officials were obviously not ready for this, and the very weak cover story feels ad libbed.
Secondly, it is very unlikely that Olmert was the target, for the simple reason that Olmert himself boarded the plane to explain to Sarkozy what happened. You can bet that if this was an assassination attack on Olmert, Israeli officials wouldn't have allowed him to stay behind, waiting for another shot from a second planted shooter. He would have been whisked away from the scene.
The most likely explanation, particularly given the Realist Zionist contents of Sarkozy's statements and actions, was that this was an assassination attempt by the Israeli right on someone who they regarded as a supporter-turned-traitor. Like Rabin.