Writer, producer, and director Robert Aldrich refused Cliff Robertson's request to attend the 1969 Academy Awards ceremony, as a flight from the Philippines to Los Angeles and back would be too time-consuming due to budgetary restraints. Robertson pleaded with Aldrich, even offering to pay out of pocket for any costs associated with his absence, but to no avail. Robertson won the Oscar for Charly (1968), and the crew presented him with a mock statuette made out of wood. According to Turner Classic Movies host Robert Osborne, after the Philippine location shooting was over, Academy of Motion Pictures Arts & Sciences President Gregory Peck greeted the cast as they disembarked at Los Angeles International Airport. Robertson was holding his fake Oscar when he got off the plane. As he was approached by Peck with the real statuette, Robertson threw the wooden "Oscar" over his shoulder. The fake statuette hit Sir Michael Caine in the forehead, causing him to bleed profusely.
While filming in the jungles in the Philippines, Sir Michael Caine seemed to have an unerring sense of direction, and always managed to find his way about. However, filming in the jungles created on the studio backlot in Hollywood was delayed on the first day, as Caine had managed to get himself lost.
When Cliff Robertson entered the U.S. Navy base in Subic Bay to do some location work, he was dressed in full military uniform, and was mistaken for an officer by the guards at the entry post.
At the time, the largest production to be filmed in the Philippines.
Tokyo firms created four hundred new Japanese Army uniforms for the production.