Factual error: When the Brainstorm project is taken over by the sinister military operative Landan Marks, he begins weaponizing the brain-interface technology and testing it on the human guinea pig Gordon Forbes. As Gordon is subjected to increasingly difficult fighter-jet simulations, Landan Marks gleefully exclaims to military observers, "Now watch this! He can take a full 10-G rollout without losing control, just by thinking about it!" In the flight-simulator cockpit, Gordon grimaces, but the Brainstorm device allows him to remain conscious and maintain control despite his physical distress. But the fact is that no flight simulator in the 1980s or even today would be able to simulate extreme G-forces as described in this film. In fact, flight simulators then and now can't approximate even low G-forces. Only a giant centrifuge can produce such forces; but Gordon is not in a centrifuge for this scene. It's simply a flight simulator.
Continuity mistake: As Mike and Karen walk the aisle at Lillian's funeral, she links her arm with his. The camera cuts to a wider angle and they're not touching. (00:59:50)
Continuity mistake: When Christopher Walken gives his wife a tape of his best memories, many of the shots are 3rd-person, of the two of them, and not 1st-person, from his perspective, like everyone else's recordings. (00:44:40)
Plot hole: The demonstration to the Board of the system's potential is ported through acoustic modems. Even in those days (early 1980s), anyone would have realized that the bandwidth simply wasn't possible at 300 bps.
Continuity mistake: From the very start, this movie's psychedelic visual effects (representing a test pattern grid) are rotating counter-clockwise in the background throughout the title sequence. This transitions to the opening scene in the lab, where the researchers are still trying to calibrate the test pattern grid. Christopher Walken, who is actually viewing the effects, complains that the grid is scrambled, out-of-phase and rotating. Louise Fletcher makes some technical adjustments and says, "What do you see, angel?" Walken answers, "Clockwise rotation." The shot instantly cuts to the visual-effects view again, to show us what Walken is seeing, and all of the grid effects are still rotating counter-clockwise. (00:00:50 - 00:03:00)