No organizer would stop a game in progress just because the electronic demonstration board suddenly ceases to function - especially in a match to decide the challenger to the current World Chess Champion - since neither the game nor the players are affected. Since the year was 1992, manual demonstration boards would have been readily available. Also, even in a normal adjournment of a game (usually after 40 moves at that time), the player on the move had to seal the next move in an envelope.
(at around 1h 35 mins) Erica is seen playing Super Mario Bros. 3 (1988) on the PC, but the game is not available on the PC. It was only released for the Nintendo Entertainment System, PlayChoice-10 and Game Boy Advance.
(at around 1h 35 mins) When Erica is shown playing Super Mario Bros. 3 (1988) on a PC, the moves she makes with the joystick as well as her keyboard tapping are inconsistent with what is shown on the PC monitor. In the next scene, she moves away from the PC but the game is still playing by itself.
(at around 1h 8 mins) Midway through the film Peter Sanderson and Frank Sedman are conferring with a computer whiz. When we see a full view of the table that the men are standing around it's not Sedman but Tom Skerritt's stand-in - his face is in full view.
(at around 1h 45 mins) During the fight scene with the water coming down, you can see a crew member with his camera covered in a clear tarp on the right side of the screen.
(at around 1h 35 mins) After the 'carefully' murder, there is an attempted murder on Kathy. And somewhere later on, Peter is taken into custody and writes the words on the blackboard, all six: Remember Eventually Revenge Is Carefully Arranged. But the Arranged murder never happens.
(at around 16 mins) When Capt. Sedman interviews Sanderson after the murder of Debi Rutlege he states that she is not listed in the directory. Yet when Kathy later goes through Sanderson's directory to look for a pizza place (at around 53 mins) there is an entry for Debi Rutlege which Sanderson has marked.