Before any one suggest it - yes i have also try to go back there and target the invisible NPC - with no luck.....
Well i have tried to petition before and i have to say i dont have any good to say about it.
Every time i have made a petitions i still not got any resonse and some time i have been online about 5 hours after i did the petition, the only time i have got a fast response was when i did try to figure out how to change my first name and last......
So i guess if i want ai xp i have to do the old school mission to get em, and mabye in a year or so FC might fix the bugg (if im still played then - start to get realy pis*** on all the new buggs & nerfs, played since beta 3 with 4 paid accounts - but i think of close em and mabye just go a frob).