Factual error: Holmes and Watson's first encounter with the French giant results in a large steel ship, still under construction, being prematurely launched and then sunk. As it sinks, this ship, which is more than 30 meters long, stands on its bow. There is absolutely nowhere in the River Thames near London where the water is that deep.
Add timeBruce Trestrail
Factual error: In the scene depicting life on Baker Street (after the "Sherlock Holmes" title), a horse-drawn carriage races through the streets of London. The only problem is, the carriage is driving on the right side of the road with others passing on the left. In England, carriages would be driving on the left.
Continuity mistake: In the scene where Watson is moving his things out of the room and Holmes is examining a body, Holmes walks and goes to get a book once he returns, and Watson says "it will probably be a factory by the river" when the camera cuts back to Holmes one side of his shirt collar is down, although both sides were popped just seconds before, and seconds later the collar goes back to being popped.
Continuity mistake: During the boxing match, Sherlock claps at his opponent and stands up to see the handkerchief. After he gets punched, the scene that shows him falling to the ground does not display the white handkerchief, 10 seconds later when he stands up it is back on the rail again.
Character mistake: Near the start, Sherlock reads a newspaper dated Friday November 13th 1890 - that day was actually a Thursday. About an hour later he reads another newspaper dated Friday November 19th 1891. If a week had gone by it should have read the 20th - a year could have gone by, but that date was again a Thursday.
Factual error: In the scene where Holmes is defending himself with some sort of electrical prod, it's clear that the tips of the prod have the same electrical potential (they are connected to the same metal). Subsequently, this device could never be used to shock anyone unless they were standing on a metal plate that was connected to the opposite electrical pole of the prod tips. If it had a Leiden-Jar type power source, it would have been expended after the first jolt.
Continuity mistake: In the scene where Holmes is jumping from the office in the Houses of Parliament, the camera shot from the inside of the office as he jumps out of the window shows that his body is not fully out of the window as he falls down (his legs are still in the room). However, the view outside of Parliament shows Holmes jump clear of the window before he descends to the river.