I don't see what's wrong with getting the kill, when you got the player to 0.5, and they run away and suicide, or give their teammate the kill (which is boosting kills).
A lot of guilds at sards have done this. Teammates will line up, and let their buddies areow them to deny a pker the kill.
If you want, let your guildmate arrow you for your strategies, but the pker who registered the last hit should get the kill.
A lot of people in sards (from my experience) have done this. Makes me not want to pk, after getting them to 0.5 consistently, then they let other members get the kill from arrows. Pking becomes super slow, and makes you want to go somewhere else.