The Mystery of the Spanish Chest - S3-E8
Continuity mistake: During the party, the colonel expresses to Poirot his disappointment for the jazz record being played, music "from the inferior races." He puts a tart in his mouth, closing his lips past the piece of fruit. Cut to the wider shot, and he is still holding a tart that sports the strawberry he just chewed on. (00:19:00)