Character mistake: When McCall put his gun to his head and pulled the trigger, he's saddened that it didn't go off. Most handguns (including the one he was using), after the last round is fired, the slide locks to the rear. He would not have made the mistake of thinking it was loaded.
Answer: During their conversation Dracula is able to move around the room without Viktor noticing it. Then Dracula is standing on top of the fireplace behind Viktor, that's why he turns his head the first time. When Dracula suddenly slams the chest Viktor is surprised to see Dracula suddenly standing in front of him so he instinctively turn his head to look at the fireplace to believe his own eyes.
Mortug