I got the event "Vengence", in which the Rival exact his/her revenge on the target by either killing or wounding him/her.
There seems to be an inversion in the "Die" possibility. When you read the description when hovering over the event button, it says target B has 50% chance to die in the hands of Rival A, but when I click and it kills the target it's actually Rival A who dies, not Rival B.
"Wounded" (25% chances) is fine, however. Target B gets the "Wounded" trait. It seems that the problem is only on the "Dying" possibility.
Numerous times, when I get this event my Monarch is actually supposed to kill his rival, but he is the one who ends up dying all the time. And to be certain, when it happens I check the possible results before clicking the button just to be sure, and I'm 100% certain it's supposed to be the opposite. In fact, nowhere does it say that the Monarch or the Rival enacting the Event is supposed to die at all.