As part of a PvP server it is common and expected that from time to time you get ganked by a higher level player. That's fine and part of the experience, however if someone 30 levels higher follows you through the entire zone just so he can send you back to the graveyard which happens to be very far away, this has nothing to do with PvP, that's harassment. As this happens with increasing frequency on Nostalrous, I think this should be counter-acted, while its not yet a huge issue, so that it doesn't become one.
There are many ways to deal with that, but the best way would be to encourage people to not farm-gank other player's that have no way to realistically defend themselves automatically. During vanilla there was a time where grey kills would reward a dishonorable kill, but that didn't really work out well for several reasons, mostly because the impact was too strong, however the general idea wasn't that bad.
I would suggest to add a feature that gives you a negative kill if you kill someone much lower level. Basically if that player would have awarded a kill and 20 honor, you instead loose a kill from the counter and loose 20 honor.
Since this would only apply to kills that grant a very low amount of honor, the impact would be negligible to those who randomly gank someone, and only affect those, who repeatedly farm lower level players.