It is griefing and you are a person of questionable ethics, in my opinion. The OP exploited a confirmed bug to kill CMDRs in a completely cowardly fashion, like all good psychopaths and sadists. If you feel that this is valid game play, shame on you.
This is Elite, not Counter Strike. As mentioned before, you Griefers will likely be all alone in Open at some point. The grown-ups will mostly play in Solo or Group.
You lose all credibility when you play the "age card"
And no, they won't be alone. A good number of them not only enjoy the hunt as the predator, but as the potential prey.