Star Crossed - S1-E6
Corrected entry: The second time the day happens, Amy comes driving up right after the near-accident, because she "saw Derek's car." Since Tru's actions didn't change the timeline throughout the car chase, that means that Amy should have shown up at the same time during the original day as well. In that case, she would have witnessed Derek cause the crash that killed Adam and Jen, and there shouldn't have been a mystery.
Correction: Before she showed up, the car was about to go over the edge before Derek stopped himself. She showed up moments later. We don't have enough information to determine what happened originally. By the time she would have arrived the car would have already gone over the edge so she could have assumed Derek just arrived like she did. Or Derek could have easily driven away as soon as the car went over the edge without being seen.
lartaker1975