After holding open casting calls attended by hundreds of Hmong in the communities of Saint Paul, Fresno and Detroit, Eastwood settled on ten Hmong leads and supporting players, all but one of whom are first-time actors. Hmong crew, cultural consultants and dozens of extras were also hired.
The actors struggle, too, with their culture being made into spectacle. Even though a real Hmong shaman was cast to play a ritualist, his expertise was overridden by the screenplay and the filming, which distorted the ceremonial scenes by making them inaccurately exotic.
Ever hopeful, actor Doua Moua, who also plays a gangster in Gran Torino, anticipates that the film will open the door to more opportunities for Hmong producers and directors. Thinking of the dozens of small production companies that make videos in Hmong language for community entertainment, he envisions giving back to his people by working with up-and-coming Hmong directors. The future, for Doua and many other Hmong, is not only to be cast by the Hollywood heavyweights but to also take a shot at becoming heavyweights themselves.
No, Eastwood understands that authenticity matters. As a consummate professional, he probably realized he had a responsibility to depict the Hmong accurately. No quick 'n' easy choices based on box-office considerations for him.
This is why his movies are a critical and (I believe) a financial success. He doesn't pander to Hollywood's tastes (or lack thereof). He doesn't add "hotties," car chases, or explosions just to spice up his movies.
I bet he never considered casting non-Hmong actors to portray the Hmong. I can just imagine his response if someone had suggested using Taylor Lautner, with his pseudo-Asian look. He would've fixed the interlocutor with his steely gaze and said, "Are you insane?"
For more on the subject, see The Best Indian Movies.