1) reveals the killer's role if he observes him at the moment of committing the crime or his victim.
2) can replace the planted evidence at the crime scene with his own (even with something very insignificant), if the killer doesn't use additional evidence, then the Thief can also plant his own (i.e., the main thing is that there are not three pieces of evidence at once).
Hey, who was talking about the nickname and that the Thief can't plant evidence during a murder? Did you read the rules carefully? It is written in black and white that the Thief watches the victim/killer and in any case can plant evidence on the killer (only a fool wouldn't), i.e., the Thief plants evidence on the killer 100%, and not on the Town, and the evidence can be VERY-VERY obvious, as in this case. It says so, so I think Kyle should be executed... but first, I'll wait for Zubr to confirm my theory.