It took them a while to look for Hercules. The domain was vast and not a good place to keep and dog without a leash. After looking for a few minutes, Tiamut dragged him out of the cells where they were keeping all those vassals, where Hercules was found dry humping one of the aliens.
Hercules might have been behaving like a dog, but he was still a demigod stronger than any of the vassals there. Thus, once he entered their cell, he could do whatever he pleased and none of them would have been able to stop him even if they wanted to. It was a good thing that he was technically dead and couldn't reproduce... otherwise who knew what else he would have done.
Either way, he was brought forward in front of Arnold who kept on looking at him with indifferent eyes. Without saying a word Arnold yanked the collar off and Hercules slowly got a hold over himself. However, as he did, memories of the time he spent as a dog came rushing back into his head.