When “The Real Mo Farah,” a documentary about the Olympic gold-winning athlete, aired on the BBC in the U.K. last month, it was front page news.

The feature doc, which had been kept so tightly under wraps even some of those working on it didn’t know exactly what it contained, revealed that the story Farah had repeatedly told about his upbringing – on talk shows and in his published autobiography – was a lie. In fact, his real name was Hussein Abdi Kahin and at 9 years old he was torn from his family and trafficked by neighbors from Somaliland to Britain to work, he says, in indentured servitude.

A co-production between the BBC, Atomized Studios and Red Bull Studios, “The Real Mo Farah” dominated U.K. headlines the week it came out, receiving numerous accolades for both Farah, who had chosen to tell his story at risk of potentially losing...