If there was no Mrs. Columbo
A lot of people have theorized about what if Mrs. Columbo didn't actually exist and Columbo just made all of that up? If that were the case, which episode do you think becomes the most awkward from Columbo's point of explanation?
Murder in Malibu, when he says the dead woman wears the same panties as his wife, and he demonstrates on the mannequin at the underwear section how if the tag was on the right side of the panties instead of the left, it meant they were put on backwards. If he didn't have a wife who wore the same kind of underwear, how would he have known that?