Hans knew that his good friend, Ryan, was a traitor to the treasure hunting team. He became quiet and blamed himself.
Watson trusted him so much, but he failed Watson's trust.
In this case, Watson didn't directly pursue Ryan's betrayal. Instead, he persuaded Hans not to attack Ryan too early.
"Hans, Ryan is still useful to us. As long as he is with us, we can constantly send the other party some wrong information. It's better than not knowing our enemy at all.
I think we can keep Ryan for a while. Anyway, he didn't cause much loss to us. It's a good thing that we take the initiative in this situation."
Watson wanted to use Ryan's information channel to send some selective information to the people behind him, which meant that he had taken the initiative. It was better than knowing nothing.
In this case, Ryan was like a knife in Watson's hand, not hurting himself.
Hans thought Watson's words made sense. He didn't want to teach him a lesson. After all, he was his best friend.