Cargolux - valid point
Lufthansa - That was a 742, and nothing "fell off"... just a mistake when jacking up the aircraft.
CAL @ LHR - Just an unexpected retraction of the nosegear that could happen on any other brand new 744... again nothing "fell off". The whole story complete with pictures is on PPRuNe.
Air Canada - The combi aircraft "tipped on its arse" through improper loading... once again nothing "fell off"
Still.... 1 out of 4 ain't bad