The address that your phone comes up with when trying to send to him is up to the settings on your phone. Some phones have contact info that comes from the phone contained Contacts list; some phones may have two sources of "contained within" info (as with phones for an elaborate SIM card); some phones utilize an external source for getting the email (or phone number) info when sending (or calling) a person. Finally, some phones may use both methods to try and consolidate all the various agreeing and disagreeing info for any of the names.

It is up to you to try and get and keep it all straight. There is only so much that a phone can assume, when being told multiple details for the same name.