The object does look uncannily like a pot lid of some kind. My saucepan lids have a metal rim, a plastic knob in the centre, and a Pyrex-type transparent lid. The obvious problem with interpreting the object as a pot lid is that it appears to go behind the wingtip of the aircraft. If it really does, it would be much too large, and in an impossible location, since a pot lid could hardly be dangled outside a jet plane in flight. But does it? I may be imagining it, but as the object reaches the edge of the wing it looks to me as if for a moment the object (and especially the ‘knob’) are in front of the wing before disappearing and then emerging from the other side. With pre-CGI technology it would probably require quite a lot of work to doctor the film of the object frame-by-frame ... Read even more
