Nancy says that Judah's discman was fell to the ground when Judah had his heart attack. Shane was jogging with Judah when it happened and has previously talked about what Judah said just before his death. It seems odd that he was listening to music while talking to his son as listening to music while jogging is more typical of people jogging alone.
During the waltz lesson the instructor counts to 4. In waltz time there are only 3 beats.