Nice trivia. One thing I don't understand, is they say the crew didn't know about the chestburster, but they had to have John setup under the table, with a fak

Nice trivia. One thing I don't understand, is they say the crew didn't know about the chestburster, but they had to have John setup under the table, with a fake torso. In the setup pic you can see he doesn't even have legs. Surely they could tell something was going to happen?