The only thing I can see is it seems like he's a bit long bodied...his dorsal doesn't really flow into his caudal but I thought the topline was decent, anal fin was a good shape, he has forward pointing rays on the dorsal and they seem to be long enough and the dragon scales seem uniform and tight looking-his dragon scaling is some of the best I have found albiet I haven't been looking long, lol.
Anything that would scream out "keep him out of the gene pool!"?
I would try to find a dragon female with better/more ray branching to improve the tail. Perhaps a shorter bodied more stout female?