Visible crew/equipment: In the beginning of the show right before Percy enters Blackadder's room you can see the shadow of some equipment moving up and down above the fire place. (00:00:35)
Visible crew/equipment: When Blackadder and Melchett leave to go visit the Queen and they close the door, the boom mike is visible in the upper left corner of the screen. (00:05:05)
Visible crew/equipment: After Blackadder has pushed Queen Elizabeth into the closet and sits down at the table, Percy "coughs". When it cuts back to Blackadder, you can see the boom mike above his head. (00:17:00)
Continuity mistake: There is a knock on the front door, and Blackadder tells Baldrick to 'get the door'. Baldrick returns with it, but the front door on the set, still in place, is still visible in the background of the shot. The fact that Baldrick knows who was at the door indicates that he's got the right one.
Visible crew/equipment: When Blackadder is about to leave Captain Redbeard and Redbeard says, "So you do have some spunk in you," you can see the boom mike pop into picture in the upper right corner of the screen. (00:12:50)
Continuity mistake: Right at the very end, when everyone is lying dead on the floor, Stephen Fry's eyes are still moving. (00:29:00)
Plot hole: The timing in the episode "Head" is completely muddled up. Lady Farrow is shown petitioning the Queen to see her husband and states "My husband dies tomorrow." placing the scene on the Tuesday (Farrow was scheduled to be executed on the Wednesday). In the next scene Percy is asked by Blackadder how the executions went; he then turns to the Ploppys and states "I've got a few notes on today's show" placing the scene on Monday (as Drake and Ethingham were scheduled for execution on Monday and Farrow's death was moved to the same day to give Blackadder the rest of the week off). Lady Farrow then enters with the death warrant she obtained from the Queen in the previous scene, seemingly having travelled back in time a day.
Audio problem: When Blackadder explains to Baldric about what he is not allowed to prepare for dinner Blackadder says "And that means no meat." There is a glitch before he says meat, it may be where they stopped recording before the sentence was finished.
Revealing mistake: When Flash says "I've got a plan and it's as hot as my pants", his moustache is seen falling off.
Revealing mistake: It is apparent that the door Flash pushes Percy through is fake. The door bends inwards like polystyrene when it should be made out of wood.
Answer: According to the IMDB.com's quote page for Blackadder The Third, it's "Aahhhhh. Hot potato, orchestra stalls, Puck will make amends. Owwwwww."
Gary O'Reilly