Characters have a curious grasp of English. For example, a note in class at the start says "your ... a tw*t" instead of "you're". Lines include "when you're in a crises", "feel the tension between Jordana and I", "me and Dad have discussed it", and "that's between your mother and I".
The pencil drawing of Oliver's mom initially appears with a single half way fold when she looked at it. When Oliver found it, it was folded twice. But on close up of the drawing, the folds have completely disappeared.
All the way at the end of the movie, Oliver and Jordana are standing right next to each other on the beach, with Jordana's dog between them. Then the camera changes and they are seen from behind. Suddenly, they are much further apart and the dog is at the other side of Jordana.
Oliver gets a VHS video of Graham's presentation from Graham's house. When Oliver's seen in his bedroom watching Graham on telly the empty case with Graham's picture is actually the size of an audio cassette (for comparison another audio cassette case can be seen to the left of the screen.) The implication is that Oliver is watching the "video tape" but the only tape device present is for audio cassette, besides which it is clear that the tape player is empty. Other views reveal that that there is NO video tape machine in Oliver's room.