Plot hole: When Columbo presents the flipped photograph to Dick Van Dyke in the final scene, Columbo insists it is correct and proves DVD guilty. But Columbo already showed him the rejected fireplace photo, which shows the room arranged correctly. It also shows the victim's wedding ring, which would be on the wrong hand according to Columbo.
Suggested correction: It's all part of Columbo's bluff: Galesko wants to get rid of Columbo as fast as possible and believes himself to be too smart, thus falls for it. Galesko might have forgotten about the fireplace photo or underestimated its importance. Even if Galesko points out the rejected photo: Columbo is already bluffing about the first photo, he can very well just claim the second photo never existed or is destroyed too, leaving Galesko in the same position as he is before he incriminates himself.
