There is no US intelligence. It was a tabloid magazine in the US that reported this, and it quoted mostly Indian sources.
Our Indian friends are humiliated and desperate after the thrashing from China so they are clinging to any hope. This is why the Indians have started to quote that US tabloid magazine.
Use common sense: The Chinese outnumbered the Indians, were armed and ambushed the unsuspecting Indians. How could the Indians have killed more Chinese with their fists? I know the Indians love to think of their soldiers as Sunny Deol but reality is not made that way.
There is no US intelligence source. Indians are getting desperate.