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.
Continuity mistake: When Flasheart hits Edmund with the gun, he swings his arm to the right, but Edmund falls to the left.
Plan E: General Hospital - S4-E5
Visible crew/equipment: When Black Adder enters the General's office after he returns from the hospital for the first time, the shadow of the camera can be seen as it peers up from the desk. (00:07:20)
Plan E: General Hospital - S4-E5
Continuity mistake: After his interrogation, Darling is able to run out of the doctor's office (albeit hobbled by the chair he is tied to) despite having been shot in the foot and having been seen visibly limping earlier.
Continuity mistake: When Blackadder and the other soldiers are about to go "over the top", you can see two other soldiers standing behind Darling. They are presumably in the upper part of the trench. When Blackadder blows his whistle, you see all the soldiers climb onto their ladders and then start to rush over, side-by-side. In the next shot, when we see the soldiers emerging from the trench in slow motion, the other two soldiers are still back in the trench waiting for Darling to climb out before they move, as the two shots were filmed in two different studios.