In the game, you meet Alyx Vance after being knocked silly by some metrocops. Your screen goes white, and then Alyx peers in overhead and says "Dr. Freeman, I presume?"|
The term "mingebag" is used to denote newbies in Garry's Mod, as it is your default name when you start the mod. So, anyone on a Gmod server named "mingebag" is pretty likely to be playing for the first time and doesn't know how to change their name.
In other news, I played the F.E.A.R. demo this weekend and put a little write-up in the News/Extras section.