During the new governor's speech in the beginning of the movie Mr. Potter walks up to Charles Adare twice.
In the ballroom scene, the plate of food that Ingrid Bergman is holding is almost empty, and then moments later is full of salad greens.
The opening narration declares that "In 1770 Captain Cook discovered Australia". While James Cook led one of the first British expeditions to Australia, other European explorers had visited the country before him.
As the characters gather for the dinner party, fairly early on in the film, the camera tracks backwards across the dining room. The table has been pushed into the path of the camera by the time it comes into view, but the candlesticks are still shaking severely from the jerking appearance of the table (their shaking lessens as the take continues).
When Adare walks into his uncle's bathroom the wall holding the bathroom door is clearly sliding to the right to make way for the camera.
Table and chair move when Henrietta walks into the kitchen after Millie's departure.
At one point in the film, a character says that employees to be fired should be given their "pink slips." The film takes place in 1830s Australia. An article in the New York Times dates the earliest use of the term "pink slip" to 1910.
Ingrid Bergman's ballgown clearly reveals a zipper in the back. The film is sent in 1830 and zippers were not being vetted for another 40 years.
(at around 1h 02 mins) By way of mentioning an invitation to a ball, Charles tells Hattie and Sam, "Oh by the way, I have a bit of news for you," but his mouth is closed for much of the sentence.
Shadow of boom-mic visible (top-right) during the ("What is your name?") Susan (Crumpet) kitchen sequence.