Exactly my point in relation to this particular incident, however, this did not occur as initiated by the OP, apparently due to the stuck throttle from the RC. One would think that in a scenario such as this, RTH would have overridden the RC command for full throttle and the AC would have initiated the return ( which in this instance it did at one point), and negated the full throttle RC command. This did not happen. Even though RTH was commanded both by the pilot and by smart battery, the AC never descended for landing due to the RC commanding full throttle. This was where my question of ATTI mode RTH originated.