This is a very interesting answer. Since bitcoin is not regulated like banks. Then we could say that the bitcoin within his wallet would no longer be part of the over all circulating supply. The total 21 million that is to be produced in bitcoin would not be adjusted. If I'm not mistaken there is at least 3-4 million that is considered at lost right now. Meaning this are within the people who forgot their password, lost hard drives and other reasons.