I will just leave my opinion here:

After you got DNA of Raa you should have asked him why he killed that Guy. Not instantly shoot him. Why? Because he could have killed that innocent for self-defence. So it would not be his fault. Also since you had sound off, you couldn't hear him say "This guy shot me so i killed him" . Also, Raa is allowed to warn you for Attempted RDM since you shot him first.

I would agree with you, if you had sound on. Then it would be Raa's fault for not saying anything.