With Mab, Lea and Jim? In the context of the books?
In real life there is no separation between body and soul and what we see as soul is just an expression of the total person and in that context Harry could not have been dead because he is now alive but that is not the dresdenverse. In the dresdenverse people can rise from the dead.
It is stated several times, Bob in Ghost Story hints that Harry was only mostly dead.. Mab says death is a spectrum, Harry had not fallen so far he couldn't return. Harry has said since then he was only mostly dead, which means he wasn't all dead. His body was kept alive, the risk was something could have happened to his soul in it's walk about, then his body would have died because there was no soul or undamaged soul to return to it. It is plausible, his heart was badly damaged to be sure, he lost a lot of blood, but he fell into ice cold water, in the arms of the Queen of Winter, immediate cool down to put him in a state of suspended animation, then on to the island, full i.c.u. set up, Dresden style, nourishment, i.v. supplied by Alfred, circulation/heart/lung supplied by Bonea, and the rest supplied by Mab, keeping the body alive. More importantly, his brain alive, which is the key. When his soul returned, Harry woke up from his coma, he still was a while healing and rehabbing after that. Metaphorically you might say he returned from the dead, but in reality he never was.