Continuity mistake: In his room, the gunman puts the revolver in the right inside pocket of his coat. He later draws the gun from the left inside pocket.
Factual error: The royal parade is supposed to be of the Yorkshire Hussars, but the filmmakers instead borrowed the King's Troop, Royal Horse Artillery, complete with guns. Although the uniform was similar, the Yorkshire Hussars was a cavalry regiment until the Second World War, when it became an armoured regiment. It was never an artillery regiment.
Answer: Re the first part, it's just a matter of word choice, not a mistake, even if it might be "wrong" from an etiquette point of view. For the second question, no, the wife of the King is called the Queen, conventionally. Technically "Queen consort", to draw a distinction from the reigning monarch, in that she has the title of Queen but not the same political power. But the husband of a reigning Queen isn't called a King, or even a King consort, generally, because in the UK a King is viewed as a higher authority, so would imply a greater status than that of his wife, who's the actual monarch. Prince Philip isn't the Queen consort, he would be a Prince Consort, but doesn't have that title, hes a "Prince of the United Kingdom." The only husband of a Queen to have held the title of Prince Consort was Prince Albert, husband to Queen Victoria. It's largely a semantic/title difference and comes down to personal preference/the will of the reigning monarch.
Jon Sandys ★