Mystery in Paris: An Airliner Flying Backwards at the French Open?

At the French Open at Roland Garros Stadium right after the Raphael Nadal and Diego Schwartzman quarterfinal match one of our Plane & Pilot staffers noticed the shadow of an airplane moving along the red clay surface and disappearing out of frame after it went into the crowd. We've got some theories. Check it out and let us know what your take on it is!

And of course Nadal won the match!