At around 15 minutes, when Ilana tells Ben to start digging a grave at the beach, the rifle she is holding swaps between being covered in sand and having no sand at all, as the camera changes between looking at Ilana and looking over her shoulder at Ben.
Hurley comments on how Richard hasn't aged in 30 years. Yet he never met Richard in the 70s.
Alex pleads with Ben to help her study for the AP exam, which is to be held that weekend. AP exams in all subjects are held nation-wide in May of each year, not September as when the scene occurs.
Ben and his father are talking about what life could have been like if they had stayed on the island. Ben is changing his father's oxygen tank during the conversation. He goes to the cabinet, puts the empty tank away, and gets a new, "full" tank. He connects the new tank to the regulator and the gauge is briefly shown. The gauge shows that the tank is "in the red", which means that it is nearly empty.