If Player A says "There is a KOS on Player B", is that considered to be a KOS from Player A, and if not, are you allowed to follow said KOS? I apologize, as I am fairly certain this has been answered before, but there are so many related titles that it was impossible to find in Q&A, and I seem to remember hearing conflicting answers from staff previously.
You can kill player A for saying "There is a KOS on <name>", as well as the original player who called it. As of right now, as shown already, it IS a valid KOS to state something like that even if its a repeat (as seen in the post made by Falcor) But if the KOS led to your death, you would want the original player who called it (not the one repeating it) to be slain and held responsible.
Keep in mind that just saying, "There is a KOS on Chastity4lyfe" without any prior KOSes, credits the original KOS to you - should it be a false KOS, you will be held accountable.