Continuity mistake: When the guy is looking for the map, he knocks a vase out of the cupboard, and it breaks. After Lester trips up, the lights come on, and there is no broken glass anywhere.
Continuity mistake: After the boat with Jessie, Bo, Luke, and the girl get stuck, you see Jessie standing to get the boat unstuck. A second later, you see that he's sitting, then another second and he's standing.
Continuity mistake: Enos posts up an "Armed Robbery" poster for Floyd Baker and Molly Harmon for a $10,000 reward but after he rips it off the wall after he sees them outside the courthouse it turns into a wanted poster for "Grand Larceny and Car Stripping" for Bo, Luke and Daisy Duke. (00:03:50 - 00:09:55)
Return of the Ridge Raiders - S2-E20
Continuity mistake: The boys are driving along an open dirt road, being chased by the Sheriff. As they meet a blue car, they wave, and you notice that there are no bushes anywhere to be seen. When the blue car meets the cop cars, there are suddenly bushes on either side of the road, poorly disguising ramps used to flip the cop cars.
Continuity mistake: When Daisy is helping Luke chase down Benny the Quill, she begins with white open-toe heels, then she is shown wearing running shoes across the rocks in the river, and goes back to the heels just before she falls in the quicksand.
Double Dukes - S4-E2
Continuity mistake: If you look closely during the first scene where Turk and Moody (disguised as Bo and Luke) reveal to Roscoe that they aren't Bo and Luke, as they peel off their faces. First Moody (as Luke) is wearing a solid light-blue shirt. When we get a close-up of his face, he is wearing Luke's traditional blue-pladed shirt, and after their masks are totally off, Moody is wearing the solid light-blue shirt again.
10 Million Dollar Sheriff (1) - S4-E8
Continuity mistake: In the first scene that Steele is chasing the Dukes in, he hits the side of the General Lee. You can see that the side is badly damaged. But in the next shot when the General Lee is taking a sharp turn and sliding, you can see that the car is repaired.
Dear Diary - S4-E20
Continuity mistake: While it's forgiven that the Generals usually have subtle changes through episodes and the series, in this episode we see a General with extremely inconsistent graphics when Bo and Luke deliver the counterfeit money to Winston. The 0 is off and the bottom of the 1 is extremely long.
Answer: Various reasons, but mainly to drive the Dukes out of Hazzard County because the family have been foiling his schemes since his and Uncle Jesse's bootlegging days.
Captain Defenestrator