"It's the reason despite knowing what Dai Chen did back then, there were no repercussions for him. We understood it and even agreed to it on some level, and should the day come when we uncover those who harmed Lai Lei, however, it ends up getting handled, we will not stop it.
The two obsidian serpents were victims in this, and their reaction was completely within their rights to do so, but it still doesn't deny the fact that an inquisitor died in their hands. We can overlook the injuries it caused to the Branch Chief and the rest since it's treatable, but a death, that complicates matters.
This is why we have decided that the moment they're caught, while we will not take their lives, they will be indentured to the service of the Order for the entirety of their lives via a soul contract.