When Lightman and Foster are in the corridor, discussing Emily's virginity, the amount of foam on Foster's drink changes between shots.
When agent Reynolds is in the hospital we see a nurse adjusting his iv. She does so without gloves and wearing rings on her right-hand finger. Nurses are not allowed to wear jewelry while working and are required to glove up doing work which involves patient contact. Although with each health care facility the policies for jewelry wear are different.