That is incorrect. They only left after US airspace reopened to the public
The Ibn Ladn family are also our friends, and they were Osama's enemy when he was still alive (they had disowned him).
After the family "disown' him in fact for years after that event they had ongoing finance tieds with him.
After a complete air flight ban in the US began during the 9/11 attacks, some commercial flights begin resuming this day. However, all private flights are still banned from flying. Nonetheless, at least one private flight carrying Saudi royalty takes place on this day. And in subsequent days, other flights carry royalty and bin Laden family members. These flights take place even as fighters escort down three other private planes attempting to fly. Most of the Saudi royals and bin Ladens in the US at the time are high school or college students and young professionals. [New York Times, 9/30/2001; Vanity Fair, 10/2003] The first flight is a Lear Jet that leaves from a private Raytheon hangar in Tampa, Florida, and takes three Saudis to Lexington, Kentucky. [Tampa Tribune, 10/5/2001] This flight apparently takes place several hours after a private meeting between President Bush and Prince Bandar, the Saudi ambassador to the US. Some think the idea of the flights were approved at that meeting (see September 13, 2001). For two years, this violation of the air ban is denied by the FAA, FBI, and White House, and decried as an urban legend except for one article detailing them in a Tampa newspaper. [Tampa Tribune, 10/5/2001] Finally, in 2003, counterterrorism “tsar” Richard Clarke confirms the existence of these flights, and Secretary of State Powell confirms them as well. [MSNBC, 9/7/2003; Vanity Fair, 10/2003] However, the White House remains silent on the matter. [New York Times, 9/4/2003] Officials at the Tampa International Airport finally confirm this first flight in 2004. But whether the flight violated the air ban or not rests on some technicalities that remain unresolved. [Lexington Herald-Leader, 6/10/2004] The Saudis are evacuated to Saudi Arabia over the next several days (see September 14-19, 2001).