I also finally watched this documentary, and I can say that I am somewhat positively surprised with the amount of good information presented in it, which I did not know before. What is proven without any doubt is that Cotten was corrupt from an early age, and that he participated in many frauds before, with the help of an even more corrupt partner (Michael Patryn), who is a convicted criminal in the US then known as Omar Dhanani.
You are right, it is strange to say the least and everyone is rightly wondering how a journalist concluded his investigation in India in such a way that he allegedly spoke to a doctor who confirmed the story and the death of Cotten, without speaking to anyone else such as the hospital staff, the police or the hotel staff where Cotten had been before. Especially if the sister of Jennifer (Cotten's wife) confirmed that he did not want to go to India, but she persuaded him to do so - and that she was the only person who saw him dead, considering that the coffin was closed at the funeral. Although some have tried to make sure that all questions have some kind of answer, I think that there are still a lot of lies that need to be revealed.
What has been unequivocally established and proven is the fact that Cotten literally gambled away most of his clients' money trading cryptocurrencies on other crypto exchanges - so the question is how he could do this without any of those CEXs reacting in the sense that they did not look for the origin of the crypto assets?