At the end of the movie, when Quartermain turns to shoot the invisible Reed and Moriarty stabs him in the back, you'll notice that Moriarty stabs him close to his shoulder - a wound that should NOT have killed him, yet it did.

What's worse is the fact that in the next frame, the dagger has moved down to the middle of his back - a wound that WOULD have killed him. The dagger moved!