At one point, Frank (Gene Evans) states "Pat made that recording while the brain was destroying Yocum." However, in the final edited version of the movie, Pat (Dr. Cory, played by Lew Ayres) makes his recording several days before Yocum is killed.
The size of the brain in the tank keeps abruptly changing size, within the same scene.
About 5-10 minutes from the end, Donovan's brain, in its glass tank, is shot with a couple of bullets through the glass, causing bullet holes and other damage to the glass. When the brain is shown again a few minutes later, the glass tank is intact.
Frank shoots himself in the left arm with the pistol in his right hand yet, in ten final scene when Pat gets into the backseat of the car and Frank slides over to give him room, Frank reaches over to his right shoulder with his left arm, as if he had shot himself in his right arm, holding the pistol in his left hand.
Frank shoots himself in the left arm with the pistol in his right hand yet, in the final scene when Pat gets into the backseat of the car and Frank slides over to give him room, Frank reaches over to his right shoulder with his left arm, as if he had shot himself in his right arm, holding the pistol in his left hand.
On several occasions, Cory each time erroneously refers to the oscilloscope as the "oscillograph." However, when the movie was made, an oscilloscope was previously called an oscillograph. It is also informally known as an o-scope, or CRO (for cathode ray oscilloscope.)
When the bank manager picks up the stack of bills to count them, he leaves a bill on the desk. He counts the rest and hands them to Dr. Cory. Neither man notices the bill left behind.