Other mistake: The URL seen on Siobhan's laptop (https://internet-search.comm7986/index.html) is obviously a fake URL.
Revealing mistake: Not long into Sarah's phone call to Rachel telling her P.T. Westmorland's real age/name, Sarah's phone is not actually in call mode.
Continuity mistake: When Art kills Simon Frontenac, the barrel of his handgun is pulled back, indicating that the magazine is empty. When he checks Frontenac's pulse, the barrel is pulled forward again.
Continuity mistake: When Gracie is on the phone to Mark and reading Helena's diary, the diary has changed position on Helena's bed before Gracie touches it.
Revealing mistake: After Krystal goes to the bathroom, Sarah's phone is not in call mode.
