Visible crew/equipment: When Kate/Bob first arrives at Blackadder's and she says, "I'm an honest hard working lad", you can see the boom mike pop into picture above her. (00:04:55)
Visible crew/equipment: When Melchet is trying to entertain the Queen and she says, "No use, Melchet, I'm still bored," you can see the boom mike pop in above her head. (00:07:20)
Visible crew/equipment: When Blackadder is at the Queen's asking for permission to get married and she approves, the boom mike pops into picture several times above her. (00:20:10)
Visible crew/equipment: When Blackadder goes to see The Wise Woman, as she gets out of bed and starts talking you can see the boom mic moving above Blackadder's head. (00:15:50)
Visible crew/equipment: When Blackadder calls for Baldrick and asks for a raw turnip, as Baldrick enters, you can see some shadow moving on the left of the screen. It's not Baldrick's shadow and there's certainly no one else in the room that could make that shadow. (00:13:55)
Visible crew/equipment: When Blackadder is at the doctor and the doctor says, "I think you are in luck though," while pointing at the board of "Principal Leech Points", you can see the boom mike pop in right above Blackadder. (00:12:45)
Visible crew/equipment: When Blackadder is called to the Queen's first practical joke and he says he didn't laugh because his head would fall off, the Queen says, "If you don't start soon, your head will fall off", the boom mike is visible above her head. (00:09:55)
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)
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)
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