Other mistake: When Lea Jansen and Dave Ryder want to leave the room, which is called the "deep freeze", they hear Kalgon and his men coming and "hide" next to the door. When Kalgon and his men enter, the movie wants to tell us that they cannot see Lea and Ryder, although they are obviously in their field of view.
Other mistake: Throughout the movie some previously used shots have been edited in, most obviously the men with the fire extinguishers from the beginning or some scenes from the party.
