The information I received below from my Japanese researcher seems to contradict that only five American's were captured on Yap during the war (two flyers from the 8/10/1944 B-24 and the three UDT men).
RESEARCHER: I accidentally found a book written by a former 323 trooper. The author (Mr. SUMI) wrote that ...One day, a large plane and two escorts (small planes) flew at the altitude of 500-700 meters, a Japanese plane at URURU a/f , YAP chased after them. At the same time, AAA exploded near of the enemy planes and the large plane leaned (banked?) and it headed south, and after that a parachute was sighted. The two escorts already flew away westward. An American was captured on the ground (the author writes that he was the first POW on the island). He was handed over to the Brigade H.Q. and an interrogation started. The interpreter was 2nd Lt. JINDAI (finance) and 1stLt. TANAKA (infantry artillery) from the ITO Battalion. The American told the interrogators that the objective for his mission was reconnaissance over Japanese positions and harbor facilities. He flew from the Admiralty Is.
The B-24 missions from the Admiralty Island’s in the summer of 1944 were 13 hour missions that never had fighter escorts. Yap Island was too far away from any base to provide fighters during this time period. A large plane with two fighters could not have happened until the fall of 1944. If a single American was captured from the event above it would have to be a separate incident. I thought I had located all the American losses over Yap (see the link below). I have not located any American losses when a larger plane with fighter escorts was lost. Please let me know if anyone has any information that might help identify this particular loss and date.