My theory is that someone in a diplomatic role in Sweden called in a couple favors to handle this. Since his request for asylum in Sweden was denied his visa there was likely to expire soon.

> Both TSA officials and FBI Terrorist Screening Center director Timothy Healy confirmed to ABC News last week that the effort to keep U.S. airspace off-limits to terror suspects has not included vetting the passengers and pilots on large private jets such as the one owned by Chagoury, which he has used to shuttle between Los Angeles, Las Vegas, New York and Europe.

I'd suspect there are similar loopholes for private jets chartered by friendly governments. But you may be right and someone in the Swedish government called in a favor.