It was an overcast Monday afternoon in late April, and Michael Oher, the former football player whose high school years were dramatized in the movie “The Blind Side,” was driving Michael Sokolove on a tour through a forlorn-looking stretch of Memphis and past some of the landmarks of his childhood. In the movie, Oher moves into the home of the wealthy white couple Leigh Anne and Sean Tuohy. They take him shopping for clothes, help him obtain a driver’s license, buy him a pickup truck and arrange for tutoring that helps improve his grades and makes him eligible to play college football. In real life, Oher went on to play eight seasons as a starting offensive tackle in the N.F.L. and won a Super Bowl with the Baltimore Ravens. Now, Oher is suing the Tuohys, claiming that they have exploited him by using his name, image and likeness to promote speaking engagements that have earned them roughly $8 million over the last two decades — and by repeatedly saying that they adopted him when...