Some people told me they thought the picture in question doesn't have enough evidence. I'd like to point out a few things in the picture that I think piece it together well enough.
1. There is only one dead blu.
2. It says the Warden has been killed.
3. In the top right corner it shows that a blu slayed themselves.
4. It is only 20 seconds into the round.
The only way this picture could be taken otherwise is if another player as Warden slayed, and then Kole, a random blu guard, also decided to slay for no reason 5 or 10 seconds after warden, because the Warden Killed message only stays up for a few seconds. The actual warden would have have to have left the server, leaving Kole as the only dead blu.