The dogtags may have been removed by the original team in 1943, and got lost because the guy carrying them subsequently got killed. It’s also possible that they left them behind before their flight.
My uncles was in graves registration in WWII. He went to a lot of plane crashes in the mountains of New Guinea. He said that most of the time dog tags were the only identifiable thing they would put in the bags.
No flyer in WWII wanted to be unknown.