[quote=@Legion-114]
<Snipped quote by Orion>

Yes, but remember that most of the population in the Vault are from 2077.
[/quote]

Well I was going with the idea that they had at least some contact with the outside world. Almost all of the vaults that were actually designed to have people live in them, rather than be part of a social experiment they had the need for at least some contact. 

So I figured that he might trade with or be aware of the existence of the vault.