Other mistake: When Deckard visits the Tyrell Corporation, he prepares to test Rachel with the "VK" machine. He is shown putting his briefcase of the table and lifting the "VK" machine out and onto the table. If you look closely, the "VK" machine is already on the table and Harrison Ford is miming the lifting - there is nothing in his hands! (00:19:45)
Other mistake: The brief chess game (four moves) shown in the beginning of the movie makes absolutely no sense. For instance: There are no white bishops on the board, but after the human player taps a few buttons, the computer says that he just moved one. Within the two moves described first, the positions of the pieces change completely. In addition, some pieces are now gone and there are new pieces on the board. It's like an entirely different game. The final move is said to have been made with a black rook, which is impossible. In the shot shown before this move, there is not a single position available to that chess piece that would result in an instant checkmate. Nothing in the editing indicates that these few short shots are supposed to be viewed as separate games. (00:04:50)
Other mistake: On board the USS Reliant as it orbits Ceti Alpha 6 the systems panels show ship diagnostic diagrams including a wire model of a Constitution class hull, something the Reliant doesn't have. (00:13:01)
Other mistake: When Rambo turns himself in after the death of Deputy Galt, policemen fire several shots in the direction of the river. No impact of the first shots can be seen at the surface of the river when Rambo seems to be hurt by a bullet. (00:31:55)
Other mistake: The creep tells us that this is the first issue, but mere seconds after the famous ending of Father's Day we see fan mail on the second page, impossible for the first issue. (00:21:05)
Other mistake: The night after burying the bird, a lightning strike projects an image of the tree outside onto the bedroom wall. However, the silhouette has nothing to do with the tree's shape.
Other mistake: In the Ring Game, Flynn throws a shot that Crom catches and returns. When the shot hits Flynn's rings, it takes out the third and fourth ring. Problem is that any other time, the impact only takes out the ring that it hit. Close inspection shows a solid hit on the fourth ring only. The only explanation is that since Flynn continues and jumps the "gap" in the rings, this was a deliberate set up to bring the end to this sequence and move the movie forward.