Mainfrog,
What makes you think BA had the complete names of pax on the aircraft before it was boarded. Suppose after the plane was in the air 30 min or 60 min the final comparisons come back through the computer (complete with how tickets were purchased etc) and whaddya know, a few names pop up? Should they turn back to London?
What if they came up past the point of No return? You don't have enough info on whether or not it was a cockup...
BTW todays flight was canceled at the request of the BRITISH gov't... You don't suppose that maybe your intellegence services suffer from the same limitations as our per chance?
Also, with flights going on the hour or so, its possible they thought the people in question were going to be on a later or earlier flight and they were rolled over further mucking up the issue.
Cheers
Wino