Other mistake: After John T's passing, the screen caption reads "1 year later" and they are celebrating his birthday. The light flash happened on his birthday and took three months to be diagnosed and die. The caption should actually say 9 months later.
Phenomenon (1996)
Ending / spoiler
Directed by: Jon Turteltaub
Starring: Robert Duvall, John Travolta, Forest Whitaker, Kyra Sedgwick, Brent Spiner
A brain tumour gave John Travolta his abilities; he dies.
More mistakes in Phenomenon
George Malley: This is good, Lace. I think you're a good cook.
Lace Pennamin: No, I'm not. I only make two things pretty well: pork chops and, um, turkey.
George Malley: Hm. Which is this?
Trivia: Nate Pope (Forest Whitaker) is an Amateur Radio operator with the call sign WB6QLF. QLF is amateur shorthand for "I am sending with my left foot", a reference to someone whose Morse Code sending skill is very bad. This is normally sent as a question "QLF?" meaning "Are you sending with your left foot?" to an operator who is very difficult to understand in Morse.
Question: If it was just a tumour that made him think more, how did he get telekinesis?
Answer: Certain parts of the brain, emotions, personality traits and learning abilities can be amplified with specific stimulation. It's believed that this can happen with psychic abilities: premonition, telekinesis and pyrokinesis. Ever get a "feeling" you're being followed or "know" that someone is lying to you?
You're describing intuition, not psychic abilities.
Answer: Yes, that's a form of ESP. When your brain cells are heightened, so is your intuition.