I used to work for a guy who was on Okinawa. He said towards the end of the war Americans began to pity the Japanese, and for the most part felt sorry for them. The last ditchers who would feign surrender (or death or injury) in order to have an opportunity to kill Americans complicated the situation.
Another factor was that U.S forces were physically and emotionally exhausted by long hard fighting, and hac very little tolerance for or patience with misunderstandings caused by language barriers. It is really a lot easier to shoot a prisoner than search him, and escort him to the rear.
The Japs were told to strip before they came out of the caves. That is why most look naked in the films.
It happened in the ETO as well, and in that case, there were a fair number of Americans who spoke some German and Germans who spoke some English. The Germans were all over the place when it came to behavior- some of them had no compunction about shooting medics, etc, while others were "correct" to the point where they put themselves on the line. When Germans went past the established boundaries, they generally got it back good and hard.
(Incidentally, about a year before my dad passed away he told me about a situation involving an ETO vet uncle that touched on some of the points brought up in this thread. Dad did not tell me how it ended - I don't know if my uncle actually ever told him the ending - but there was no good outcome possible.)
Mr. niteowl77
“Take them to the rear,” was usually code for “get them away from the front line and kill them.”
Hacksaw Ridge has some illustrative scenes.