Why did Cole cry out the words "I'm sorry!"

By chapter 23 Cole feels ready to do the dance of anger that Edwin had been telling him about. It naturally comes to him as he lets out a scream and dances around the fire. He again relived the bear attack, and he cries asking forgiveness for attacking Peter. He then forgives those who have hurt him, and he cries profusely. As the scene closes with Cole collapsing, exhausted, crying, halfway through the night, the Spirit Bear looks on, unbeknownst to Cole.