Taril: I still think, that was not his plan. He just got caught. And as Anska said, he explained, what his plan was after you free him.
He quite literally states his plan when you talk to him in the dungeon.
He quite literally states he won't leave until the goblin leaders are dead because the Grove is in danger while they're directing the goblin army.
It may not have been his initial plan for why he went with Aradin and his group, but it became his plan by the time they were in the goblin camp and were ambushed.
