Not sure this will answer your question, but when I do a search in my contacts, those results displaying with an email address are because the search criteria (like your example of "har") is also included in that email address. Example: searching "har" comes up with results for Harry Jones whose email address is harryj@something.com, so his name and email address are displayed. But for Harry Smith who email address is smithh@something.com, it doesn't contain "har" so is not displayed.