After seeing their so-called leader blasted away like that, the large men from the Dark guild no longer wished to continue on. They surrendered there and then, they had no reason to fight and no one to protect.
Soon after, the main Redwing leaders stormed into the castle while the others waited outside and recovered. There were many who were injured and needed to rest and on top of this. They had a job to do in collecting those that had died, not just from their side but from the Dark guild members' side as well.
When they entered the castle, they could see where Gary had been thrown and landed, but there was no sign of him anywhere. It looked like he had gotten up and run away, to where though, was anyone's guess.
Last chapter of this arc and we will be moving into a new one :)