When Eddie and "Jennifer" are walking around the house alone, "Jennifer" is trying to tell Eddie that she's really Sara. But By the time she is explaining that her name is actually Sara and not "Jennifer", Eddie has disappeared. She doesn't find him until later... But from the moment she finds him (and he is talking to her) he calls her Sara... but he never actually heard her say that. He was gone. Also, after they all get back together, a few of the other people start calling her Sara as well....but no one actually heard her say that her name was Sara.
The Terror Incognita roller coaster is actually The Hulk roller coaster in Universal Studios, Orlando.