Thanks for the replies. From what I can gather, a member of the tech crew does a walk around when the slats/flaps are stowed, the aircraft is eventually pushed back, engines started, wings totally reconfigured for flight either before or shortly after the ground engineer disconnects (if thats what dispatched means). However, even if the wings are reconfigured while the ground engineer is still connected, checking them is not an item on their checklist. So it was just through luck, rather than good procedures, that in this case the problem was detected prior to take-off.