Reza Aslan is very “evangelically” atheistic. The purpose of the show seems like it is designed to put all “believers” in a bad light. Documentary evidence or not, this sect is not typical of Hindu, and it *is* outrageous to present this is in what is marketed as a general introduction to beliefs.
I didn't see that episode, but to be fair, I doubt anyone claimed that this practice was representative of Hinduism. However, it's true that viewers who know nothing about the subject might come away thinking that it is representative.
Reza Aslan is a Sufi Muslim, not an atheist, so his agenda isn't so much showing that all religions are bad as the liberal view that all religions are equal and morally equivalent. As I said in my earlier post, if that was his intent, he failed miserably with his choice of examples.