Why Sam Waterston is not credited in the cast?
He s the architect that takes Holly and her friend on a date to the Opera.
He is not listed in the credits of the film and not here in IMDb.
If you click on the 'See Full Cast' link and scroll all the way to the bottom of the 'Rest of Cast Listed Alphabetically', he's the last one listed, as David (uncredited).
The one just above him is Tony Roberts as Norman, Mickey's former partner - I hadn't realized that he wasn't listed in the credits either.
“She doesn’t get eaten by the eels at this time.”