At about 30 minutes in Robert and Shrimpy are talking in the library. Shrimpy is seen from the back and the front as the scene changes while they talk. His right hand from the front is on the glass he's drinking from but from behind his right arm is down at his side.
When Isobel asks Tom "Why not invite Miss Bunting tomorrow night?" at the 28:53 mark, her lips (seen from behind) don't match at all what she's saying.
Prince Kuragin refers to his missing wife as "Princess Kuragin". Russian wives take their husband's surname with a letter "a" appended, so he should refer to his wife as "Princess Kuragina".