Sillier things have been reported. I recall reading about police being called to investigate a safe apparently dumped in the street after a supposed robbery. They duly arrived, examined it, and then set to trying to lift the object into the van, without any success. After nearly giving themselves hernias it dawned on them that the 'safe' was in fact a traffic-light control box, permanently set in the pavement.
Regarding UFOs (I have seen many, but they don't remain 'U..' forever!) - let's hope this hapless spotter never claps eye on the many other heavenly phenomena that may catch you out! Like sun-dogs, iridium flares, noctilucent clouds that can sometimes take on bizarre shapes, weather balloons, etc.