That Wily Atta

Here's something I learned a few days ago. In discussing Said Bahaji's possible involvement in the recent airline bombing plot, Captain Ed recounts his involvement in the 11-Sep-2001 plot, including this:

While Atta traveled to Afghanistan for training, Bahaji maintained a false front in Germany, covering their absence in order to throw off suspicion.

Now this got me thinking.

Cast your mind back to Atta's alleged Prague visit. The 11-Sep-2001 commission blithely dismissed it, on the bases of two pieces of evidence, one negative and one positive: 1) nobody flying under that name left the USA or entered it on the dates in question, and Atta had never been known to fly under a false name before; 2) his mobile phone was used while he was supposedly away. Now the flaw in this argument is obvious, and it was lampooned from the day the report was released. He'd never been known to fly under a different name, as far as these remarkably uncurious commissioners knew, and he might well have left his phone behind (especially if it wasn't a WorldPhone), and someone else may have used it.

Now follow the logic. Thecommissioners seem to have believed that Atta was something of a creature of habit, and that they could look to his known history to know what he was or wasn't likely to do when out of sight. He wasn't known to have flown under other names, so we can assume he didn't do it that day. But now I learn that he had a history of having someone lay a cover for him while he took a trip that he didn't want anyone to know about. And that the commissioners knew this.
Given that history, how could they have given any weight to the fact that his phone was used in America while he's alleged to have been in Prague? Wouldn't that be absolutely consistent with his MO? As for his not having flown under false names, if his Afghan trip was supposed to be so secret that he had Bahaji covering for him, are we really to believe that he used his own passport?