I saw the documentary last night, and that is certainly the position of the crew members who were interviewed in the documentary as well. Israeli air force observation planes had made frequent low passes over the ship prior to the attack exchanging waves with the crew and the recordings of the radio chatter between the Israeli pilots and the controllers directing the attack operation from Israel showed that everyone knew it was a US ship that was under attack. As the attacks started, the Israelis were also jamming the usual tactical and emergency frequencies used by the ship to prevent any calls for help from going out (until a crewman was finally able to get out an SOS hours later after making a jury rigged, makeshift antenna). The program alleges that the reason the Israelis felt compelled to attack and try to sink the defenseless, intelligence gathering ship was to keep hidden from the US the amount of Arab land it was intending to take over during the course of the then ongoing war with the Arab states.
Why did LBJ administration go along with the coverup? The program alleges that the Israelis had a 2 prong strategy to get the US to sweep everything under the carpet. It was leaked to Johnson through his advisers with Israeli connections that if he continued to pursue the issue and allow a full investigation which would reveal that Israel had deliberately tried to sink a US Navy ship, the Israeli propaganda machine would get the word out that Johnson was only picking on Israel and making an issue of this accidental and regrettable attack because he was a closet anti-Semite. At the time Johnson was still thinking of running for another term in office, and if the label of anti-Semite stuck, his chances of raising campaign funding from many of the usual wealthy democratic-supporting donors would dry up.
The second inducement Israel offered to the US to go along with a coverup was to give the US access to captured Russian supplied anti-aircraft missiles that were currently also being used by North Vietnam to take down attacking US aircraft in the Vietnam conflict. By being able to study the missiles at first hand the US was able to devise more effective countermeasures against the missiles.