email address ambiguity

In the profile's supervisor field, supposedly e-mail addresses are used as a primary key to people. However, users can easily add a new variant, for example paraic.sheridan@computing.dcu.ie seems to be in the system while I start typing psheridan and if I hadn't wondered why it isn't auto-completed I would have entered my supervisor creating a 2nd identity. Or did you implement that the system maps all email variants (in TCD they have even more as you can omit the scss part) to one person?