James Oberg has collected a whole slew of excited UFO reports from French observers, occasioned by the Falcon-9 second stage deorbit burn on 11th November. The orbital path passed over the Pyrenees and the display was visible from much of Western Europe and North Africa.
A selection of reports:
« [Y]esterday evening, Monday 11/11/2019 around 17h55, I observed above the end of
the Ardeche river canyon, between Saint Martin d'Ardèche and Saint Just d'Ardèche . Flying
slowly in a West-East direction, at an indefinite altitude but definitely in our sky, our atmosphere. The "main lighting" in the form of a camembert was noted, the arc of a circle to the front, coming from two sources side by side at the front of the object, and a line or a ray slightly offset towards the 'front’ left. [I had] no time to focus with my poor smartphone, just a photo and a seven-second blurred video, all in maximum optical + digital zoom, too bad. What a surprise...»
--Jérôme JAQUIN - Link to video
« Hello, seen on LSA 38260 at 17:52 too, Flight Radar helping it was Lyon-Ajaccio at sunset. The image does not do justice to the magnificent plume of light generated by the aircraft's headlights on the clouds Yes! You are not accustomed to observe the sky: last night the conditions of light and humidity allowed good observations like these. I saw the phenomenon and cross checked on Flight Radar in RT! What evidence do you have that it was not an airplane? »
--Cyril Bargeton, pilot
« Strange object in the sky that I filmed near Gretz Armainvilliers this Monday 11/11/19 before
18h. I do not know what it was, it looked like a plane with landing lights, but I did not actually see a plane, it made no noise at all. I do not know if it was an aircraft, a drone, a helicopter, a glider, a weather balloon, a cloud of insects, a meteorological / spatial phenomenon / paranormal or UFO ... We do not know .. No clouds other than the fog that followed the object like a luminous cone.»
In recent years I’ve collected an amazing range of analogies and metaphors from witnesses trying to relate the appearance of a space rocket plume to some familiar earthly item. Aside from the spirals and spheres and other highly unusual forms, the descriptions of simple exoatmospheric plumes has inspired analogies to headlights, to parachutes, to ice cream cones, but never before this France overflight had I ever heard a witness compare it to a slice of Camembert cheesenote 1. But the French being French, I should not have been surprised. Mais pourquoi pas!?
• Witnesses exhibited standard inability to judge distance
• Witnesses exhibited good ability to describe shape variations
• Stronger than usual delight in imagining it was an alien UFO
• Bizarre coincidence with moderate [5.4 Richter] local earthquake
• Some witnesses accurately noted unusual feature that plume PRECEDED rather than FOLLOWED the object [it WAS a deorbit burn]
 Note that the French call a pie chart "a camembert." So it's a very common descriptor of a circle segment.