User blog comment:Joekido/Joekido Arc Analysis: Introduction/@comment-2226235-20150419055627/@comment-24.235.56.170-20150420002427

The body needs to remain alive, for the shadow to be alive. Otherwise, why wouldn't Moria just kill his victims when they're passed out from losing their shadow? The shadow represents the person's soul; no life, no soul. This is explained when Brook explains Moria's powers to the Straw Hats.

But I think that most of the Marineford inconsistencies could be explained away if you're willing to cut Oda some slack.