BA264 is the outbound flight number. The jet bridges are usually stowed out the way for arrival and only connected for departing pax (assuming its the same for 767) as the mobile lounges are used for disembarkation. As the incident happened 30 mins (if the timings are correct) after the aircraft parked, and there are no pax desperate to give eyewitness statements, I would suggest that the jetbridge collided with the aircraft not vice versa.