Regarding your last point, I always assumed the wine steward was somebody else who was off-camera. Vito Scotti maybe was the restaurant owner (who might not have gone along with the trick if he had known about it), and the other guy might have been a waiter?

After Carsini,Karen and Columbo finished their dinner in the restaurant; i likethe way Carsini says he can't wait to see what Columbo has selected for the after dinner wine. Like it's a given that everyone does this.

Agree. Pleasance definitely makes this episode one that I like to watch it over again.

Columbo wanted to know if it rained on Tuesday because Rick‘’s car was left uncovered. Who would leave a convertible top down in the rain. Especially if they loved their car. Since, the coroner reported the death to have occurred on Tuesday, the car was probably planted after the fact because the inside was dry.

I think i read on this site that this episode was Peter's favorite episode!