I completed Dragon’s Reach on my ranger and got the reward. When I did it on my thief, I didn’t get any reward.
The first toon I did it on, I had started the instance, but was in a party and all with me got the reward. The second toon, I was also in a party but had not created the instance; however the instance creator did get his reward.
I have double checked and the story is showing as completed for that toon.