Plot hole: When Bo-Tat is purchased the Village Elder insists that Lihn go with Bo-Tat, it is CLEARLY established at this time that A) Lihn is an orphan and B) his parents were both killed in the war. For two-thirds of the movie Capt. Doyle repeatedly comments that Lihn can't be trusted because we don't know who (NVA or USA) killed his parents. There is no possible way that Spc.5 Farley wouldn't know this. However, halfway through the movie (on the river boat) he asks Lihn where his parents are and how they died. He couldn't possibly be ignorant of this, since he took part in at least two of the prior conversations.