I don't really know anything other than the fact that he got shot, and my mum only found that out fairly recently through his military records. Apparently he never said a word about the war. Nor did my grandad. My family's military history is not terribly impressive
I do know my grandad came back from the war despising the British empire. He spent a lot of time stationed in Trinidad and he couldn't believe the poverty he saw. Began to dawn on him that everything you were told about the glorious empire was bull****.
Funny the lessons people seem to take from their time at war. Both him and your Indian friend ended up hating the British