That is a logical argument Wakey, but that still doesn't solve the problem. See, one way or another, Kingsley IS alive. Because, if you noticed, my username is in orange, which is the graduates color. Now the graduates are usually considered as alive and hence, Kingsley is alive as well. So the question is not if he is dead or alive (which was what you and Vincent were answering) but WHY is he alive.
As to that question, there are thousands of answers. Perhaps Vincents avada kedavra spell missed, but Kingsley faked his death. Perhaps the green light was a different spell. Perhaps he had a horcrux? Yes, there was also a possibility that vincent did not mean to kill Kingsley, but your logical argument sort of ruins that. However, perhaps Vincent was too weak to kill Kingsley with a simple spell like that?
Alas, with so many solutions, it is better if we ignore the problem in the first place and give no exact reason as to why Kingsley is alive. We will just need to accept the fact that Shacklebolt is in fact, fortunately or unfortunately, back. >=D