When Viktor is killed, you see 2 perfect fingers on the hand that was completely shot off before.
While on the run, 3 men in blue jumpsuits are shown gathered around a fire in the woods.
In the fire; a log is visible, perfectly cut and quartered, yet they have no tools or equipment with them.
When Lisa is left tied up in the basement, she gets the knife with her foot. When cutting her bindings, she uses the dull side if the knife.