Visible crew/equipment: Back and Forth: When Blackadder first goes into the time machine to get the items from Baldrick, and the door goes up, you can see a crew member pushing the door closed, wearing a red shirt. (00:05:45)
Visible crew/equipment: After King Richard has been crowned, Blackadder, Baldrick and Percy return to their chambers and start cheering. When Blackadder says "We're safe, and I am a prince of the realm" you can see the boom mike move up in the right corner of the screen. (00:16:50)
Visible crew/equipment: After Blackadder has his haircut, the camera zooms in on his foot. He lifts his foot revealing a red tape marker on the floor. (00:21:50)
Visible crew/equipment: When Blackadder returns to the castle after rounding the sheep, Prince Harry says "Ah, Edmund." Blackadder then walks behind one side of the wall. The shadow of a boom pole can be seen on the right side of the wall as he does this. (00:02:40)
Visible crew/equipment: When Harry tells Blackadder to be in charge of the welcoming of King Richard's return, as Blackadder turns around and walks against the fireplace saying "12 months of chasing sheep.", if you look closely on the top of the fireplace you should be able to see the shadow of the boom mic moving. It's quite hard to see, but it's there. (00:03:45)
Visible crew/equipment: When Harry comes to see Blackadder and asks how the entertainment program is going, Harry says that St. Leonards himself was a eunuch. As it cuts to Percy agreeing, you can see the boom mike move right above Baldrick. (00:08:40)
Visible crew/equipment: Just after Edmund, Baldrick and Percy get up from sitting by the fire, and before the line "The Black Adder will be King next", the shadow of the boom mike can be seen on Baldrick's hat - it moves upwards quickly so can be hard to spot. (00:06:15)
Visible crew/equipment: In the final shot where Percy and Baldrick have entered the room and said their lines, as it fades to black the crew can be heared applauding.
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 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 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 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: 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: 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)
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: 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: 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)
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