A.K.A.-47: To avoid cluttering the main page, here is a list of all fictionalized (or not) firearms in the game and their Real Life counterparts. Some of the names were changed to those of their real life counterparts in patches:
Thirty-Eight — Colt Police Positive
Brokk 17C — Glock 17C
Colt Anaconda — Colt Anaconda
McLusky .50 Caliber — IMI Desert Eagle
Braddock 9mm — MAC-10
Lassiter Killmatic — Uzi
Utica M37 — Ithaca 37
Jaegerspas XV — Franchi SPAS-15
Jaime Sue — Remington Model 700
Steyr Aug — Steyr AUG
Accidentally Accurate: Meta-example. In the French version of the game, there is a typo in one of Therese Voerman's lines (when you spoke to her after the "Slashterpiece" quest), in which there is written "Therese" where she would be logically speaking of Jeanette. Which actually makes sense. It could seem to be a clue unwillingly told (she was very upset at this moment, so she could have confuse the names), foreshadowing the reveal that they are the same person, but it is actually really a mistake: the voice actress did say "Jeanette" and not "Therese".
Development Hell: You know why this is the only non-Valve game to have the Source engine? Let's just say Troika's difficulty with Valve is the main reason why.