Continuity mistake: When Sherlock is fighting the Russian, he falls on a cart filled with seeds, which cover his right eye. When the angle changes, a frame later, the eye is clean.
Revealing mistake: When the movie starts, there's an aerial view of London's rooftops. The smoke coming out of the very first chimney doesn't move, revealing it's a painting.
Factual error: In the scene where Renè was dying, Dr. Watson examines the dying man and the poisonous arrow that hit him, and concludes that the venom used was curare. Curare is a paralysing poison that causes the body to relax to the degree that respiratory muscles stop contracting and the victim dies of asphyxiation. René on the other hand perished in strong cramps and foaming of his mouth.
Continuity mistake: On the wedding day, the bottle under Holmes' car changes positions between shots.
Continuity mistake: In the sequence where Holmes and Watson escape Meinhardt's arms and munitions factory with the help of the gypsies, Watson is clipped by a bullet in the slo-mo sequence at the bottom of his rib-cage on the right side. Later, in the train, he is seen stitching his wound on the left side.
Factual error: When Watson is pinned down by Moran at the arms factory in Germany, he hides behind a large artillery piece. He looks around and sees a pair of hearing protection. They appear to be modern hearing protection ear muffs, wrapped with cloth to make them look period. They have plastic clips to detach the ear cups from the metal band, which gives them away as being modern. They appear to be Peltor style hearing protection.
Audio problem: In the beginning when Holmes "shoots" the dog, Gladstone, with a dart and Watson says "What have you done to Gladstone now?", look closely and Watson's mouth doesn't move.
Continuity mistake: Sherlock looks at the ring of a murdered man, who was killed in a blast along with about a dozen other men in Paris, and the ring was plain. But later, the ring is shown again, and this time it has the letter M on it, a large letter, and it is very ornate - nothing like the other ring.
Revealing mistake: During the shootout at the German arms factory, one guard is firing an M1888 Mauser rifle at Holmes, Watson, etc. However, when he fires it, the bolt handle is up, but we still see a muzzle flash from the rifle. This would indicate the muzzle flash to be computer generated and not a blank from the rifle.
Factual error: The map shown in the factory scene uses the post WWI Western boarders of Germany, when it should have included northern Sleswik (today in Denmark) as well as Alsace Lorraine (today in France). (01:18:30)
Continuity mistake: In the scene where Watson goes to the telegraph office and finds it is locked, he kicks the door in, visibly damaging the frame. But once he comes out the frame is fixed and the door is lockable.
Suggested correction: When Watson is leaving the telegraph office the door frame is still visibly broken, but apparently not enough to stop the door from closing and latching.
Continuity mistake: When Sherlock Holmes has been taken into the alley by Irene and is confronted by her escorts, in one shot the braid of the wig worn by Holmes is down his back and in the next shot it is over his shoulder, in the front. (00:02:45 - 00:03:30)
