After they've been looking for Hayward for some time a patrolman finally tells Columbo "Det Columbo we found Hayward. He was at home" Columbo says "took a long time to find him at home"
Another one of my favorites fittingly comes from A Stitch In Crime where Columbo and Mayfield are talking about the roommate Marcia and Mayfield suggests that maybe she knows more than she's saying and Columbo replies "actually sir I think she knows less than she's saying"
trivia
Nita Talbot who played Marcia was once married to Don Gordon who played Alvin Deschler in Negative Reaction.
I love the line in Murder Under Glass when Paul Gerard asks why Columbo thinks Vittorio was in some kind of trouble, and Columbo replies:
"Mainly because he was murdered, sir. The two, trouble and murder, they seem to go together. At least that's been my experience, sir."