Cheeky1
Yae warsh wif' wutr
I agree with mostly with what you wrote. But at the same time, who amongst us hasn't ever told lies?
I believe most children lie in an attempt to evade a foreseen negative outcome. Some lie because they're stupid and don't know any better. Some lie in order to look better than what they actually are - this doesn't equate to the person not being capable of being this good, though.
Perhaps he believes he was under-utilized. ...doesn't give good reason to lie about his accomplishments - this only blemishes his actual accomplishments...which was, giving the benefit of the doubt, honorably serving his country.
Either way, he wouldn't be the first service member to embelish or outright lie about his accomplishments while serving.