When Sharpe and Ross go to retrieve Pyecroft, neither of them is wearing any headgear. Never mind army regulations, riding around in the desert and mountains bareheaded all day, they would get burnt and are risking sunstroke.
At around 27:48, when Sharpe introduces his wife Jane to Colonel Brand, over her shoulder, you see a red car drive in the background from right to left.
When Sharpe rolls over a dead Frenchman he blinks.
When the Rocha fort blows up, look closely and you can see bits of masonry flutter to the ground showing it is not a real fort just a large set piece.
It makes no sense for the French to put an actual, invaluable powder magazine at risk when it is all a ruse anyway.
Never mind Shellington getting the Shakespeare quote wrong ("Good night, dear prince" instead of "sweet prince"). The main thing is that this quote is wholly inappropriate to use as a non-ironic salutation when taking one's leave for the night after dinner as a guest. In the play, the quote is uttered by Horatio while Hamlet is dying in his arms, the focal point of a terrible, heartbreaking tragedy with lots of treachery and violent murder.