When Darcy comes back to Rosings after his unsuccessful proposal, we see him go up the stairs to his room. In the next scene, after he starts to write the letter, he goes to the window, and when the camera zoom out it seems that the room is on the ground floor.
After Darcy dives into the water at Pemberley and encounters Lizzy there, his hair is wet when they speak. Only a few moments later, he hurries out of the house to see her again, and his hair looks dry.
When Mr. Darcy first appears at Pemberley, the shadows of the actors are quite long, as if towards the end of a day as the sun was low in the sky. Yet later, after Mr. Darcy has changed clothes, the shadows are far shorter, indicating the sun was higher and it was earlier in the day.
After Mr Darcy has written his letter to Elizabeth, we see it lying on the table surrounded by quill shavings, even though we saw him write the letter with a steel tipped pen.
Elizabeth is invited to Pemberley and plays the keyboards, which are distinctly harpsichord sounding. Georgianna Darcy plays next and the instrument has changed into a piano.
Although it could have been adapted to activate an electric doorbell in modern times, the button next to Mr. Collins's parsonage front door - seen when Mr. Darcy exits following his unsuccessful proposal to Elizabeth and identified as belonging to an electric doorbell - is clearly the pull-knob of a mechanical bell, attached to a wire inside that travels through pulleys to activate a mechanical bell on the wall.
In the drawing room at Longbourn just before the soldiers are
to leave Meryton, Mrs. Bennett is talking to Col. Forster with Mr. Bennett and Wickham looking on. At one point we hear the conversation happening, but the shot is from another time when they were not talking to each other.
Jane refers to the Gardiner children as her nieces and nephews in the letter which Elizabeth reads in Lambton. They are actually her first cousins.
On the way to their last dinner at Rosings, Maria mentions it is the eleventh time. in a later scene, she says they dined nine times at Rosings.