Payakan is exiled and shunned as a killer justly.

....And he knows it. And hates himself for it. And considers sentence just too. Because in a way he IS guilty.

Fair warning. VERY controversial topic. Needles to say, Payakan is one of my favorite characters in whole two movies.

His people are pacifistic. When attacked - they flee. It's their way.

Upon witnessing death of his mother - he rebelled against the Tulkun way. Gathered a small army of young tulkun and na'vi. Attacked RDA ship. Got everyone killed. While fleeing and surviving.

Off course other Tulkun hate him and call him a killer. In a situation like this - many humans would do likewise.

Imagine if in movie Jake went Toruk Markto. Lost the battle. Got whole clans killed. Survived and ran away.

Imagine how he must feel. Likely hate himself more then his kind do. I suspect his exile is in many ways self imposed even. A truly tragic character. Yet unbroken and noble.