Revealing mistake: When Queen Elizabeth arrives in disguise, Blackadder welcomes her and is about to open the door to the closet, but you can see the door is being pushed up from the inside, probably by a crew member. (00:16:50)
Factual error: Baldrick becomes Blackadder's navigator. The problem is, WWI aircraft did not carry navigators; they carried either only a pilot, or a pilot and an observer, and observers were officers. (00:15:30)
Revealing mistake: When Percy is holding the 'Green' in his hands, light of the green reflects on the wall behind Blackadder. However the way Percy is holding the 'green' in front of Blackadder, Blackadder's shadow should be on the wall behind him, but it isn't. It's obvious green lighting is used to light up the back wall. (00:18:20)
Revealing mistake: When the Baron punches Baldrick into the cell wall, it wobbles. (00:17:20)
Continuity mistake: When Blackadder and Melchett are about to punch the German guards in the groin, Melchett has his hand on a paper. When it cuts his hand is no longer on the paper. (00:23:00)
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)
Continuity mistake: When Blackadder's plane is shot, we see the bullets hit the side. In the next shot of the plane, not only is the side intact, but fuel is coming out of the bottom.
Visible crew/equipment: When Baldrick is called upon to demonstrate the type of clothing required when visiting France, the edge of the scenery can be seen behind him on his right in the area he enters from.
Visible crew/equipment: During the general's speech about how Blackadder is the person to organise a concert party, look at the entrance to the trench. In one shot you can see a crew member moving a giant cloth. You see mostly the movement, but you can catch a glimpse of the crew member's face. (00:06:50)
Visible crew/equipment: In the first shot of the theatre play, you can see the boom mike quickly entering the picture to the left on the screen. (00:01:40)
Factual error: At Ms. Miggins' when she says, "There's ever so much hard work," you can see her wearing a bra under her corset. Bras didn't exist at that time. (00:06:35)
Other mistake: When we first see the plane that Blackadder and Baldrick are flying, the machine gun on top of it is firing. There are 3 mistakes here. 1) We don't hear the gun fire. Cannot be argued by the plane drowning it out, as we later hear the Red Baron's gun firing. 2) In the next shot, the gun has stopped firing. 3) The fact the gun is firing is ignored by Blackadder and Baldrick. They are too busy on keeping the plane level - the whole flying scene was obviously archive footage of WWI planes flying.
Suggested correction: OK a few points. 1. The baron and Blackadder are flying different kinds of plane. One could be louder than the other. 2. Gunners have to stop occasionally. So the gun stopping isn't a mistake. 3. We don't know for definite if they are ignoring the gun. This is speculation at best.
Revealing mistake: After Blackadder accidentally kills Smedly with one of the suicide pills, he starts ranting about how useless Smedly is as a hero, because he was dumb enough to fall for the old 'poisoned cup routine.' As he does so, you can see the supposedly dead Smedly behind him, still breathing normally.
Deliberate mistake: Whenever a punch is thrown in this series, the punch either stops before it hits the person or goes beside them. It's most obvious in the last episode when General Melchett says 'Excellent native cockney wit' and punches Baldrick.
Continuity mistake: Blackadder chucks up George's helmet, and it gets riddled with bullet holes. When the helmet comes down, it comes down at an angle, revealing that it had been passed down. (00:04:30)
Deliberate mistake: There are several historical dates wrong in this episode. For a start, Prince George didn't become Prince Regent until 1811, and yet this is set before the Battle of Trafalgar in 1805 (as Black Adder gives Wellington some advice on it). Similarly, Wellington didn't get the title "Duke of Wellington" until 1814. Again inconsistent with being pre-Trafalgar.
Continuity mistake: "Blackadder Back and Fourth": Blackadder and his guests are going down stairs. Blackadder is first, George is second, Melchett is third, Elizabeth is fourth and Darling is fifth. Blackadder gives his notebook to George. When they arrive downstairs, Melchett and Elizabeth are ahead of George. This is not logical, since the stairs are too narrow and they could not have passed George. (00:03:40)
Continuity mistake: When the Shadow shoots at Baldrick to get rid of him, she is aiming over his head but the shot lands at his feet.
