When Ryan is walking Theresa to her mother's house, they walk past a parked yellow car. Shortly after, they walk by the same car.
Near the start of the episode, Summer and Marissa are walking through the school campus. As they sit on a bench Marissa is holding a book and a bottle of water in her left hand, the camera then changes and the book is gone.
Julie attempts to poison Caleb by opening up his Ambien sleeping pill capsules and pouring the contents into his margarita. The prescription sleep aid Ambien is only available in tablet form.
2.23 - When Julie realizes that Caleb is having chest pains in the pool she throws the glass on the ground and dives in the pool to save him. If you watch her throw the glass you can clearly see that she is already holding broken pieces of 'fake' glass which she throws and we then hear SFX of glass smashing.