You probably got the torque close with the method that you used, but the optimum method is what Bill posted above. I am not sure that I understand why the manual that you have stated to pack it with RTV. When I did mine it was leaking even after a good mechnic put a new seal in, I removed that one and noticed there was slight scoring on the inside of the rearend where the outer edge of the seal sits. So I put a layer of RTV around the outside edge of the seal before I put it in. And I always put red and tacky grease in the v groove part of the seal to keep it from getting destroyed until gear lube can get up there to lubricate it after the change, plus it provides a layer of protection in there. I learned this from my dad, who was a mechanic for 35 years. It always worked for him and I never had a leak from seals that I have replaced using this method.
Where is it leaking from? I never put RTV on the splines either. And from what your post says you put RTV in the v groove portion of the seal? That could of destroyed the sealing nature of the seal, as it will harden up a bit and distort it.
It is possible that the crush seal got screwed up, even though you marked it, when retightening it down, causing the pinion to move in and out making it leak.
Not taking anything away from your abilities but you may want to take it somewhere and have them change it, if it leaks again then you have a warranty with the procedure done and just take it back

Sorry probably not much of a help.