Getting a lawyer would help you with both criminal charges and reputation when all is said and done.
there is a common misconception that only guilty people need lawyers. I would go as far to say that innocent people need lawyers even more, especially in a situation this complex.
People have been telling Zhou that since the AurumXchange thread was first posted. He chose to ignore that advice. The wisdom of that choice will probably become apparent sooner rather than later. Obviously the return of funds in no way guarantees that there'll be no criminal investigation of the MtGox breach and the attempt to launder the proceeds of it and any such investigation would look for evidence which validates or refutes Zhou's claims story.
Everyone associated with Bitcoinica should have sought legal advice following the MtGox breach because common sense should have told them that the method of intrusion meant that they were all under suspicion.