There are large number of other texts/journals that tells his story differently. He was defeated so badly at the entrance of Indian peninsula that he had retreat and finally succumbed to his injuries.
Doubtless yours is a text from the Indian perspective while the parent's narrative is from the Greek/Macedonian/Western perspective. I don't have standing to say which is more or less likely, but both are probably engaged in some amount of motivated reasoning or selective memory (hence the continuing mystery of Alexander's death).
One has to realize that historical recordings have rarely, if ever, been impartial. If you have two opposing accounts, the truth, with some probability, is somewhere in between. We will never know for sure though.
Could you provide a link to some of these sources? I've never seen the story portrayed that way. Even if we assume that all Greek sources are biased surely at least one of them would mention Alexander having been injured in combat in India, but none do.