Wow, seriously dude this isn't exactly rocket science. Its not griefing if there is a mission to do it in the game. Your example is flawed because there is no quest in wow to stand on top of a quest giver, its obviously griefing and ive seen Blizz give out warnings for doing that.
If your really actually truely believe its griefing, which i dont think you really do and are just trolling badly, then report this action to Bioware and see the response you get. The force tells me you will be dissapointed.