Exchange account (set not to sync contacts) replacing local contacts.

Got a employee who has his own iPhone 4S 5.1.1 He has a few email accounts on his phone (IMAP), and our exchange account through Google apps. NONE of these accounts are set to sync contacts.

He already has a contact for "John Doe" locally on the phone with his personal email and phone number he has set up manually. But recently he has discovered that the entry for "John Doe" on our exchange server has replaced what is on his phone. No phone number or personal email, just his work email.

I physically checked the phone, there are no contact groups on there, just locally stored ones or duplicate contacts.

What do?