
They can't just unalive him. They realize that he also manipulates guides to set traps to damage center. If I recall correctly from novel, he causes another guide to unalive and they weren't even at the center. So they need to figure out how he's communicating so that they can protect the guides and capture/take him out.
Calling captain kang when it looks like he's a Major. Also find it interesting that he's pulled into the meeting. He'll be leading the clean after Jin is done.