When the group first visits the old house and enters the basement there's a light bulb flickering. When you look closer you can see that it's a new model without the old wire type which used to cause the disconnection and therefore the flickering. Which means the flickering light you see is fake.
The "Gold" coins that Elliot and his niece find are NOT gold at all, they are US Peace SILVER dollars minted in the 1920s and 30s.
When Elliot wants to view the dead file he found, the archivist tells him to use gloves because the documents contained are very old, and they may be damaged by greasy or sweaty fingers. However, when they are discussing the content, she is touching the documents barehanded herself. Elliot is seen wearing one glove, but he too touches the documents with his other, bare hand.