In Noah's bedroom, Peter hides in a trunk and he throws all the clothes on the floor. When Noah comes in, no clothes are visible.
When Peter and Emma are at the table in Emma's flat drinking bottles of beer, the label on Peter's bottle is facing towards Emma. In the following shot, the label is facing towards the other way. As well as this, Peter's hands constantly change position during the conversation, from wrapped around the bottle to clenched together on the table.
When Peter and Emma are at the movies Peter tells Emma, "That's what the Sadness Sisters are for, right?" Although he is speaking, you can clearly see that he is chewing during that line and not speaking.