Mafia 101. Disputed Island

If you're right, it wouldn't be hard to figure out who Kosha's teammate was. We don't have that many people who might use such tactics, and Kosha isn't one of them; her gameplay is more straightforward.

There's also the fact that the patient's mana reduced the defense, so he might not have been planning to kill (you can run into Rick). If that's the case, it only confirms my theory.

Added 1 minute ago
I'm also wondering, if Kosha is the patient, who could she have "invited" to her team first...