I read a review of the documentary today. The writer was somewhat critical in that the producers suggest several theories as to what took place but make no real effort to validate them other than asking Lorance to speak to the various possibilities of what took place.
One of the criticisms was that Lorance, who is gay, might have been targeted by soldiers in the platoon who found out about his sexuality and targeted him. The writer says they producers of the documentary alluded to this, which would be a big deal if true, and then just quickly moved on without digging deeper into the possibility that this took place.