There IS a loss directly off the end of a whip type of TX antenna and it would be better not to point directly at the plane. That being said I must also say I have never had a problem doing so as the loss is relatively small.
My biggest concern is "What the heck were you flying so far away for???????" As a relatively new pilot this is a very poor idea and it is easy to become disoriented at distances and this may be what actually happened. It may also have been the RX battery or another problem of course.
1200 feet?, that's 4 football fields away. Much too far for a novice IMO.