A lot of folks are also immigrants, who need to wait close to a decade to become citizens to be able to demand anything.

In the western world the law is the answer to most problems, but that's not possible in developing worlds where the judicial system is ineffective, biased and sometimes corrupt. In many situations, the laws hinder the countries from becoming better.

What is Hindu fatalism? Hearing the term for the first time.

Karma. If something happens to you, it is your actions in the past either in this life or a previous life which are the original cause. Hence you are just receiving back the same as you have given. The problem with ignoring someone in trouble is those people are actually missing the chance to create good karma by helping those in need.

Also, reincarnation played a part in the American understanding. They were moving on to a new life and you wouldn't want to interfere.

I'm not saying that this was a sophisticated understanding. These were random American service men send to support the airlift to Burma. All I'm saying is that this was a common phenomena in the early 1940's in at least part of India and it's unlikely that it was the result of the British-Indian judicial system of the time.