Turns out the guy was indeed on official business:
(CBS/ AP) A Qatari diplomat who sparked a bomb scare after sneaking a smoke in an airplane bathroom was traveling for a consular visit to see an imprisoned al Qaeda sleeper agent.
A State Department official and another person close to the matter say Mohammed Al-Madadi was going to meet Ali Al-Marri for an official visit. Consular officials frequently visit foreigners held in the United States to make sure they are being treated well.
An administration official tells CBS News State Department reporter Charles Wolfson that Al-Marri, an al Qaeda member picked up after 9/11, is the only enemy combatant not being held at Guantanamo Bay because he was arrested in the United States. The U.S. government cut a plea agreement with him, which involved jail time, and he is now in prison in Colorado.
Qatari Diplomat Was to Meet Jailed Terrorist - CBS News