The Czechs stand 100% behind their information.
That's what I understand.
For what it's worth they have a VERY good intelligence service.
I think it's this simple -
They had a local Arab student on payroll. He saw Al-Ani meet an Arab fellow on the April date in some Prague public location.
After 9/11 Atta's pic was broadcast. The student said that was the guy. Atta is distinctive looking, so not surprising.
Czech's said it was probably Atta. Ever since factions in our govt. have strained not just to have reasonable doubt, but to quash this sighting. I think it has to do with Iraq more than Atta. Right after 9/11 Bush stepped up talking about Iraq. Unlike Afghanistan, keeping Hussein in power involved a lot of money and the interests of several important foreign nations who struggled for two years to keep Hussein in power, while trying not to seem so. An Iraqi link, however tenuous, to 9/11 would hurt these interests.
Or it's some other motive altogether.