Revealing mistake: When the family's car is about to be hit by the ambulance as they try to escape downtown, Gerry is driving and his wife is up, leaning over the passenger seat talking to their daughter. The camera angle changes to a view from behind, and as the ambulance is about to hit, we can see there is nobody in the car and the ambulance driver is wearing a safety helmet. This is viewable in just a few frames.
Revealing mistake: When Gerry cuts the woman's hand off you can see it's an obvious fake arm and stump.
Revealing mistake: During the first major panic scene downtown, as the family get into the RV, one of the shots shows a man in a blue hoodie being 'changed' by the virus. He writhes on the ground in front of a taxi - the lettering on the door of the taxi is backwards, showing it's a reversed shot.