This is actually one of the best episodes of the new series.
I enjoy it very much: plenty of clever clues (the raking on the pathway to the sea-cottage, the champagne cork, the lack of the shadow on the mask etc ...).

Very very good: and Columbo is at its best (considering this is a "new episode"): I also like the way he repeatedely watch the film to get disturbing details.

Great smile/smirk on Creighton's face when Columbo fumbles (is that being redundant?) around starting to read him his rights.

I don't think it was scripted. I think Dabney coleman was starting to crack-up laughing.