When Watson pulls the filing cabinet draw open, he uses the first two fingers of his right hand. When the camera switches so you can read the plaque on the front of the draw, all four fingers are curled around the handle.
The land grant / crown grant that was given to the Musgraves by a King Henry, lists King Henry as being King of "Great Britain, France Scotland and Ireland." This is in error, since there have been only "8" King Henry's in England's history, the last being "Henry VIII" in the 16th century. England didn't become part of "Great Britain" until 1707, with the "Act of Union" passed under Queen Anne. This occurred 160 years after Henry VIII's death.
There is also some doubt regarding the use of "France", since France oftentimes either wasn't a united country or existed side-by-side with England, thus making for confusion. The English king in question, would likely have referred not to "France" as part of his kingdom, but to which territories (such as Normandy) he controlled.
The head on Holmes' incredibly quickly-pulled bitter at The Rat and the Raven varies considerably from shot to shot - and the pint seems to be mainly foam, which any pub drinker would ask to be topped up.
As Holmes & Watson were tucking into their breakfasts, Watson had his dish and spoon in his hands, then in the next shot, he is to be seen picking his dish and spoon back up again without having put it down.
Just after the butler finishes telling Watson about the flighty girl's description of a ghost she alleged to have seen, the camera angles switch, making Watson reach for his open book on his desk twice.
When Holmes is on the floor firing the gun at the wall there are seven holes when he is done firing. Seven shots are heard. The pistol appears to be a six shot .38 caliber revolver. Since he was conducting an experiment, there was no opportunity to reload.