From: BRANDO THE UNAUTHORIZED BIOGRAPHY by Charles Higham
"Pontecorvo denies that he mishandled the extras. He said that, according to Italian rules, there were three categories of such players, and they were always paid three different salaries. Naturally, he added, the lowest-paid category was for the blacks in the crowd scenes. Pontecorvo insists that he was not influenced in the least by racist feelings. Pontecorvo adds that Marlon 'would be furious with me if I raised my voice in anger when a black extra was incompetent. But I felt that I should treat incompetence in a black man and white with equal firmness.'
"With only a few days left to shoot, and more than sixty days missed due to his absences, Marlton walked out of QUEIMADA after a particularly violent quarrel. Producer and director were left in an impossible position, with a huge financial commitment and an unfinished movie. Weeks went by. Producer Alberto Grimaldi pleaded with Marlon to return. But he flatly refused to return to Colombia under any circumstances. After discussing several possibilities, Grimaldi settled on Morocco, of all places, as the new location. At least if was dry. Marlon finally yielded and agreed to return to work there. It was a nightmare trying to create an environment exactly identical to that found in the wilds of South America.