As a metal gear solid fanatic I am sickened by that statement. The silencer = stealth. Stealth = Metal gear solid. Metal Gear Solid = Konami. Silent Hill = Konami.
This is in fact a Metal Gear refrence, according to the 'offical' Silent Hill 3 guide I own (How much creedence this lends it, I dont know).
However, I very much doubt that Solid Snake, Naked Snake, or any of the other members of FOXHOUND are running about in Silent Hill spraying graffiti. I think it is basicaly an element to have people thinking "Gee, what if blankety blank had happened when I blankety blanked here at blankety blanked and opened the door", thus generating inquiry and countless theories transformed into fan-fictions.