They didn't just research the Fallout universe, but it seems they went so far as to even research Fallout's ancestry back into the 80's. I am of course referring to the 'Guardian Citadel' from Wasteland, a predecessor of Fallout. Could it be that they carried the name forward to it's current counterpart, the BOS Citadel? Not THATS thorough!
So...whats a guy gotta do to get a Meson Cannon and Proton Axe in a weaponry expansion pack for Fallout 3?