Continue to defend al qaeda? Even though they continue to take full responsibility for it. Even if the bin laden confession video is not bin laden then it is very likely another al qaeda operative playing him. You would deny 9/11 at first too if your base of operations was about to get bombed. If they are innocent then they dont seem to be trying to convince anybody that they did not do it.

How hard is it to believe that muslims are fully capable of planning? And the fact that the use of bombs (and thermite) would have been impossible?