From Wikipedia:
[quote]Tarantino responded that Lee was "kind of an arrogant guy" and asserted that Lee's widow, Linda, wrote in Bruce Lee: The Man Only I Knew that he could beat Muhammad Ali. The passage was Linda quoting a critic. She wrote, "Even the most scathing critics admitted that Bruce's Gungfu was sensational. One critic wrote, 'Those who watched him would bet on Lee to render Cassius Clay (Ali) senseless if they were put in a room and told anything goes.'" Tarantino stated, "If people are saying, 'Well [Lee] never said he could beat up Muhammad Ali,' well yeah, he did." In 1972, Lee himself stated: "Everybody says I must fight Ali some day. ... Look at my hand. That's a little Chinese hand. He'd kill me." Lee's protégé and training partner, Dan Inosanto, also rejected the film's portrayal of Lee. Polly further stated that Lee "revered" Ali and that Tarantino's film "is not only completely inaccurate, it turns Lee into a disrespectful blowhard and jerk." Shannon responded to Tarantino by stating: “It’s a little disingenuous for him to say, 'Well, this is how [Lee] was, but this is a fictional movie, so don't worry too much about it.'"