I had my first real ninja yesterday. I was on a Strat Live run, and [Pattern: Truefaith Vestments] dropped. As there was no priest in the group, we decided to free roll it. After the roll, which I won, a warlock looted the pattern and hearthed.
So I contacted an officer in his guild. It turned out that it was the warlock's brother who was playing the character, and the real warlock sent me some gold in an effort to make up for the ninja, which I shared with the other group members. It's possible that he could have been lying, but I didn't really care.
Apparently the warlock was a tailor, and the warlock's brother learned the pattern for him, which amused me greatly.
All in all, it was an interesting experience. In my mind, it just reinforces the notion that the whole "pass on blues and epics and discuss" is a bad idea. Need/Greed takes care of the vast majority of cases.
As another random observation, the group was really competent for a pickup group. I think dropping the instance cap to 5 has done a lot of good for people's skill levels.