I think this is pretty convincing, very plausible, and they were likely executed as spies shortly after. The Japanese had no problem at all executing people at the time. Spent some time on Wake Island which was one of the most interesting places I have ever been. It was attacked at sunrise the same day as Pearl Harbor, but because it is across the dateline it was the Dec 8th. The marines held out for about 3 weeks but eventually fell. Around a 100 captured civilians were executed in 1942 shortly after finishing a runway. All the captured Marines, there weren't many, were sent to POW camps on the mainland were most died as well.