A BETTER ENDDING
SPOILERS
I never liked who the bad guy turned out to be, IT was WAYYYYYY to clear from the first moment you saw him who it was going to be so i had these 2 ideas which i believe work better.
Sean Patrick Flanery should have been the bad guy, After he dies we should have found out way towards the end when they check the body it isnt him and he had switched it with one of the helpers. Faking his own death and the way he acted all afraird of blood and crap this is why i thought he maybe the villian. It would have thrown off any clues if it was him or not.
2nd idea
Stallone could have turned out to be a crazed killer and that the man who killed his girlfriend was really dead but Stallone lost his mind after her death and became a killer himself.