Even if he does return the coins I'm pretty annoyed. He has made DRK appear more volatile than it is and wiped some value off people's holdings.
I doubt all coins will be returned... if he was dumping them like he did, then it's possible that not even 1/2 of it will be found (in BTCs - as he was selling at a loss). I'm kind of sure actually that I'm gonna lose BTCs with the ccex story.
As for DRK, there are two ways to interpret the aftermath of the "D(a)RK anomaly day"... one is that DRK is volatile, and the other is that DRK is extremely resilient despite what happened. Trading at 0.0015-16 vs 0.0020 in very small exchanges, when people actually knew that there were periodic dumps down to 0.001, is really something.
If the "stealer" was the same dumper, then that means that the dumps are over with and cheap DRKs from stolen BTCs = over. From one perspective, it's actually good that there were these dumps, evenly distributing the coins to small buyers, otherwise this stockpile would be hanging over our head in the future.