I figured out what is going on. Tuohy was not in Durham to race, she was there to train. Running a 5000 on tired legs against good competition was the last major bullet point in her training plan. The 1500 was simply a means to an end. That's why she went out fast (but stayed under control). She was setting herself up to have to dig deep during the 5000.
There was never a question of doing the 1500 at NCAAs. It's only ever been a training tool this season, including Saturday evening. Of course KT would have liked to have won the 5000 at ACCs, but that's not the real prize.