Then they should have "avoided the appearance of impropriety" by speaking English and acting in a way to avoid suspicion. I agree with another poster who said some Middle Easterners seem to get off on tweaking us.
Frankly I think it is rude for Americans to insist that people from other countries, during PRIVATE conversations, speak English, a language that is foreign to them. If I'm Italian, and I'm with other Italians, I'll probably speak Italian. No law against that. Now, if I were in some business establishment in America, trying to purchase something, I should have enough command of the language to make myself understood, but this was not the case.
According to the story, these Iraqi men were doing nothing more than speaking to each other in their native language; the one that is most comfortable to them. It was some other passenger who got unruly because of his own fear.