I am jealous that you have actually seen a bona fide UFO—at this stage of my life I have a lot of trouble believing stuff that I have not personally experienced.
There are just so many scam artists out there....
I also saw something I cannot explain, but while it was quite clear and distinct, it was not close.
However, I agree that UFO manifestations are demonic in origin and would be a very likely or plausible explanation to those deceived individuals who are left behind at the rapture.
Just another reason that it fits that the end times are now and could not have happened before. There would be no good explanation for the disappearance of that many people.