Blooper

During the scene in which Roger has brought Holmes magnifying glass to Holmes room, Holmes throws it to the floor and Mrs. Munro enters and picks it up, Holmes hair is alternately combed or disheveled from one shot to the next.

One of the scenes where Holmes is writing up his memories of the old case as they come to him, he passes his pen from right hand to left, puts it down with the left, then when he picks up his drink with the right, a different camera angle shows the pen is in that hand between his fingers. Cuts show the two situations one more time each.

The Train in the opening sequence is made up of British Railways Mark 1 carriages in the post-1956 Maroon livery. When Mr Holmes alights from the train in the next scene at the railway station the carriage is in the British Railways pre-1956 crimson and cream livery.

Right at the start, the aerial footage of the steam train shows in some shots lots of steam billowing from beneath the train - one shot is cut in showing none, no sign of any at all.

Mr. Holmes wakes up to have a flashback with him and Mrs. Kelmot in the garden. There is a close-up of Mrs. Kelmot's hand holding his card between her index and middle finger. In the first shot her middle finger is in front of the card and her index finger behind it. In the following shot her fingers have switched positions.

The very first scene is an aerial shot of a train steaming though the countryside. It goes past a semaphore signal which is in the "down" or "stop" position. The train should slow down and come to a stop, but it doesn't.

While the various vintage motor vehicles in the film look suitably new and recent on the outside for their 1947 time period, interior shots in two different cars show the cloth and mohair upholstery and interior headliner as extremely old, worn and stained, clearly showing their approximate 70 years of age, with no restoration for the film.

The fountain pen with which McKellen's Holmes is writing his memoire is a Parker first made in the early 1980s. Though Parker had a major presence in England from the period of World War I that particular pen did not exist in 1947. The mechanical pencil with which he marks the diary and the dip pen he uses to write the letter to Mr. Umezaki are correct for the time.

The film is set in 1947 prior to the nationalization of the railways, but the train in the opening sequence has the British Railways post-1956 crest on the tender and is hauling British Railways Standard Mark 1 carriages which were not introduced onto the railways until 1951. The engine hauling the train is an ex-LMS Railway Jubilee Class locomotive which would not have been seen in Sussex which was served by the Southern Railway in 1947.

In the opening scenes, where the train is passing through fields of crops, there are vehicle tracks in the crops that are made by modern spraying vehicles driving in parallel passes for spray boom coverage. This was not done in the 1940s.

Robert's bedside light is a MacLamp No.8 - appearing a decade or so before it was actually designed.

The mixer tap for the kitchen sink when Roger and his mum Mrs. Munro had an argument appeared to be too new / too shiny. It didn't look like something that would be around in 1947.

When Holmes is remembering Watson's departure from Baker Street, 221b and the house opposite are shown and the street itself appears to be a cul-de-sac with a block of apartments at the end. In reality, that particular part of Baker Street contains shops with apartments above, and the street continues across Park Street and into Regent's Park.

Holmes (perhaps forgivably for 1947) repeats the mistaken idea that "the queen runs the colony and the workers do the work" - in fact, a queen bee is no more than an enlarged egg-making machine at the service of a worker collective, which will slaughter her should she falter, while other worker bees create a replacement queen. Also when the colony grows too large, it is the workers who make the decision to swarm, by starving the queen which both lightens up her body and forces her to take flight.