I'm a bit perplexed about his healing, actually. If he really did regenerate his entire body back from being reduced to a skeleton, where'd the material to form the body come from? Are his cells able to make proteins and such out of air? And if a single cell is enough for him to regenerate his whole body, why aren't there Wolverine clones everywhere? You shed lots of cells every day, aren't those cells enough to make a new Wolverine?
I cannot answer the original question without having some answers of my own first.
PS. A thought occurs. inb4 'A wizard did it'.