I received 220 Feathers for "Your efforts at Dun Crimthain Watchtower have not gone unnoticed". Participants: 1 | Player Kills: 1 and a Duration of 9min32sec
The only issue is that I have not killed anyone, nobody has been fighting at the tower since I arrived there, no player kills were recorded at all since I joined the server.
I should not be receiving any rewards. All I have done was kill some tower guards after capturing a flag in the RvR Task zone.
[EDIT] What I think happened is that a Midgard player wiped in the tower guards before I even logged into the game and by hitting a guard I got participation in this "siege" and the rewards for the "enemy kill". (I am on ALb right now, so the Mid player dying to Hib guards could falsely count towards myself getting rewards for a player kill)