I'm not sure I understand this. Your comrade only informed you about these events after you both had left Alaska, but you were able to discuss them with your NCO afterwards? Did you have the same NCO on the later base, or did you call your old NCO in Alaska? How much detail had your comrade given his NCO, considering he didn't even mention the events to you at the time? What kind of details had been given the NCO by previous occupants, if in fact they were given the NCO at all and not to someone else, making the NCO account 3rd generation at best.
Also, you originally dismiss the possibility the events, as told to you after you had left Alaska, couldn't be caused by the child because he was a toddler, but then state that they happened over 'several years'. The difference in how a kid moves about between, say, 2 and a half years old and 5 and a half years old is considerable.
These are the kinds of tales where my sig becomes useful.