Columbo had to be pestered into hassling johnny cash at the beginning of swan song

In Grand Deceptions, Columbo does two things that he also did in Murder Under Glass (the only other time that I can remember). First he tells the suspect that he dislikes him. From memory:

MUG: I admire your talent but I don’t like anything else about you.

GD: You know, Colonel, the way we always agree with one another, that's amazing, considering the fact that we really don't like one another.

He also tells them that he suspected them right from the start:

Paul Gerard is a suspect because he didn’t go to the hospital when his dinner companion died of food poisoning.

Col. Braillie is suspected because Columbo thought he was too arrogant to be cleaning mud off the floor.