Think about the title to this post. It doesn’t assert that all or even most UFO witnesses are liars. It doesn’t say they are cranks, under the influence of alcohol or drugs, or otherwise buffoonish. In my experience, people who report UFOs are anything but. What the title does suggest, however, is that reports, even detailed ones, really cannot be deemed as evidence that what is seen is in fact extraterrestrial. In principle that may be the case, but that determination must be made on other grounds.
Why? Because of the high potential for mis-identification and the inclusion of mistaken details. For more, check out this episode of the Exposing PseudoAstronomy podcast!