In RANSOM FOR A DEAD MAN, Columbo asks Leslie's assistant how he can bring himself to work for a woman, and he really seems to mean it seriously, instead of in a bantering way. Most people would probably call that moment "a product of its time" and not think that much more about it. But even though he isn't pictured as all that "enlightened" about the subject, Columbo isn't exactly pictured as much of a sexist either. I can't help wondering whether he was entertaining the idea of the assistant being some kind of accomplice, and partly for romantic reasons, and whether he was baiting him just a little with that kind of talk.
The funny thing is, the movie shows Margaret watching that scene of DOUBLE INDEMNITY, which of course IS about a man and woman getting rid of the woman's husband partly so they can have each other, so Levinson and Link had to be thinking of the whole Double Indemnity plot. So the idea of Columbo at least entertaining that idea about this character makes a little sense in this story.

It was simply a sign of the times, just like the digital watch in "Playback" and the three-thousand dollar VCR in "Fade in to Murder".

Sort of on the same topic, just happened to catch Make me a Perfect Murder this morning, and when Kay Freestone held up her Emmy, Columbo said something like "Oh my, aren't you a clever woman."

Seemed to say it like he was surprised...