what we see now is that this was actually a fairly major ground prang in the dark with a building partly destroyed with a fractured wing leaking fuel -
i do not know how long the pax sat on this 747 for but a full dark cabin with emergency vehicles outside dealing with damage and leaking fuel i would not be surprised if the cabin crew may have been on tenterhooks awaiting an EVAC order from the flt deck...
even with my many years of operational aviation experience i would not have been too comfy sitting on board for very long in this situation especially in the dark
i do not think for one moment the BA crew would be panicky but they certainly would be anxious due to the unknown factors occurring.
an EVAC in the dark there (the area was poorly lit) again would be undesirable but i guess the crew were monitoring this in case it was deemed necessary. even if the LHS only was used it was dark (and raining?) and could well have been chaotic despite the professionalism of BA crews.
all rather unfortunate