Not my place to say what staff should do but they need to do something other then clicking a harassment report about this and closing it. It's in the game rules that players can enjoy the game with out being harassed and the PKers are breaking a clearly written rule. Also no we're in the announcement did it say anything about pking someone that's playing the event so.
Personally I would warm anyone that got reported and was witnessed doing the harassment or make TOT locations that are safe.