The damage would more than likely have been caused by the door coming into contact with the Highloader i have seen it happen a few times at BHX normally it would be reported to the engineers who would remove the panel to be repaired or replaced at a later date. It is mush beter to fly without the panel than risk flying with a damaged one that could be ripped off during flight and who knows what damage could be caused to either the leading edges of the wing or even worse if injested through the engine