Interesting that you highlighted that choice of words, which stuck out for me, too. I find it just incredulous that Dubya ever referred to that Marine as "boy". His wording of the incident seems to be changing with each account. I find that telling, too.
BUMP and mark.
That's ridiculous.
Asking about someone's BOY would be commonplace here in Texas. It is not derogatory in any way.
I referred to my own child, serving Spring 2002 in Afghanistan as a "kid". And others alternatively referred to my "child" as a kid, a young lady, etc. It wasn't offensive whatsoever to me. Folks who knew her from the time she was just out of toddlerhood even referred to my daughter as "our girl". I loved 'em for that reference. She was over there fighting for each of us; and these folks were sharing with me their pride in her.
Sure beats what the local libs in San Francisco were calling my "kid".
The President was doing the same; he was being polite and friendly. At worst, Webb could have said "He's not your "boy". But the response is: I never said he "was" my boy. See how stupid Webb's behavior was, yet?
In this context "boy" is Texan for "son", as in "How is your son?".It is in no way intented as an insult. Does that explanation help?