Revealing mistake: The bomb that is thrown at the Prince explodes before the lit fuse actually burns down far enough. (00:03:15)
Factual error: When Blackadder has disguised himself as the Prince and is speaking to Wellington, Wellington says, "I have with me here the most recent briefs from my General in the field". Blackadder, deliberately misunderstanding, replies "If you would like to pop them in the laundry basket". Blackadder is referring to the short, tight style of men's modern underwear, known as briefs, which were not invented until the 1930s.
Answer: That's the standard British pronounciation.
Moose