The director showed about 90 minutes of "If God Is Willing and Da Creek Don't Rise" at the National Association of Black Journalists convention in San Diego on Saturday. The film is a follow-up to "When the Levees Broke" about the devastation of Hurricane Katrina.
It picks up with the New Orleans Saints' Super Bowl victory and chronicles the impact of the spill on people who have yet to fully recover from Katrina.
When asked if BP cooperated he said, "Nobody was speaking to me from BP." A call to the BP press office wasn't immediately returned.
He also called on President Barack Obama to "bring the hammer" on BP and make the company pay.