Hello...this is a reference to Assassins Creed that i noticed in the game.
Spoiler alert: This may contain a spoiler. Dont Read further if u are playing or going to play this game.
So, in final missions where Hoyt cuts Jason's finger,he cuts the ring finger.This is a certain reference to Assassins Creed where the ring finger of left hand was cut so as to make space for Hidden Blade.
Ubsoft owns both AC n FC so it may be a direct reference/Easter Egg to AC..What say? :)
Btw, loved both AC n FC..kep it up Ubi! B-)