OK, my perhaps unwelcome take on this... IF the BA crew was indeed informed that an unknown person had apparently approached the aircraft on foot whilst holding on the taxiway, then I believe that they should have taken this far more seriously. A careful search should have been requested. If that meant a taxi over to some holding apron, then so be it. If that meant shutdown of the inboard engines, then so be it. If that meant a return to the gate, then so be it.
As others have pointed out, the event of an individual hiding in a wheel well is not uncommon. But the event of a security van actually apparently seeing someone do this is unique as far as I know.
Last edited by RobertS975; 30th Aug 2012 at 18:05.