When Phoebe and Piper are working with the horsemen trying to find their friend and Prue the objects on the table move frequently while everyone is standing around not touching them.
When Piper freezes the scene after the car crash, Leo doesn't freeze; up until now, he has always frozen and she has had to unfreeze him.
When Piper and Leo are in the car, about 3 minutes in, a crew member can be seen reflected on the car.