Omalu’s is ground zero in the debate surrounding head injuries in the popular sport. His story inspired the film Concussion, starring Will Smith, which opens Christmas day.

The Nigerian-born forensic pathologist is said to have discovered chronic traumatic encephalopathy (CTE), a degenerative brain disease found in people who have experienced repetitive brain trauma, such as concussions. But when he brought his findings to the NFL, he says the league attempted to discredit him, rather than face the potential threat to players.

That has since changed. Earlier this month, the Washington Post reported the NFL intends to discipline both individuals and teams that violate its concussion protocols moving forward. Penalties could include fines or suspensions.

But while Omalu is likely to become more famous with the release of the film, the filmmaker has been criticized for taking some liberties with his story. The film has reportedly omitted certain facts and exaggerated others, according to a detailed analysis by Slate.

Omalu says it was his 2002 examination of Steelers great Mike Webster that led to the breakthrough. The legendary center, who joined the Hall of Fame in 1997, died at age 50 after experiencing signs of dementia. But Omalu says when he examined Webster’s brain, he quickly noticed things weren’t right.

“I had to make sure the slides were Mike Webster’s slides,” Omalu told the PBS series Frontline in 2013. “I looked again. I saw changes that shouldn’t be in a 50-year-old man’s brains, and also changes that shouldn’t be in a brain that looked normal.”

The story of his battle to convince the NFL to take concussions seriously plays out in the film (though it was seemingly toned down to avoid the NFL’s ire), but there’s more to Omalu’s story than the two hours can contain.

For one thing, there’s the story of how early he began working on advanced studies. At age 16, he began attending medical school at the University of Nigeria, graduating with Bachelor of Medicine and Bachelor of Surgery degrees. He completed his clinical internship in that country, but came to the U.S. in 1994, where he got an epidemiology fellowship at the University of Washington. The following year, he became a resident at Columbia University’s Harlem Hospital Center and eventually trained as a forensic pathologist. He holds a total of eight advanced degrees.

Some medical journals and brain researchers interviewed by the Associated Press, however, think Omalu might be getting a bit too much credit, saying he neither discovered nor named the disease as he claims.

“Chronic traumatic encephalopathy has been around for decades. It’s not a new term,” said William Stewart, a neuropathologist at Queen Elizabeth University Hospital in Glasgow. “The only thing I would say that Bennet has done is that he identified it in an American footballer.”

Omalu strongly denies those accusations, saying they were born of professional jealousy.

And though the movie focuses on his battles with the NFL to recognize the condition, Omalu’s not stopping with the pros.

In recent weeks, he has launched a campaign to stop children from playing football and other high-impact sports up to and including at the high school level, saying the athletes are not old enough to know the risks that come with the sport.

“It is our moral duty as a society to protect the most vulnerable among us,” he wrote in the New York Times. “The human brain becomes fully developed at about 18 to 25 years old. We should at least wait for our children to grow up, be provided with the information and education on the risk of play, and let them make their own decisions. No adult, not a parent or a coach, should be allowed to make this potentially life-altering decision for a child.”