Visible crew/equipment: As the camera moves in on the bull that is about to be grabbed by the vampire, if you look under the bull, you can see two men hiding behind it. You can see their legs. They are probably there to keep the bull standing still. When it cuts they are gone. (00:26:05)
Continuity mistake: In the beginning after Dr.Frankenstein has awakened his monster he turns around and runs against the window. As he runs you can see a rack of a kind standing in front of the window. When it cuts the rack is gone. (00:00:55)
Answer: After being killed - "murdered" as Dracula stated several times - by Van Helsing, Dracula made a deal with the Devil to regain his life. Carl tells his story when telling Van Helsing and Anna everything that he has learnt.