Recently we've been noticing an issue where when searching for a user in Skype For Business/Lync 2013, a different user will show up in the search results. Doing some research, this seems to be related to "proxy addresses" as I notice the user that shows up incorrectly in place of the actual user (we're searching for) has their email address added as an alias (smtp) address in Exchange. So we search for user A, but User B's name shows up. User B's email address (an ex-employee that isn't in Exchange anymore) is added as an alias (smtp) address as part of User A's email addresses in Exchange.
The link below seems to describe our issue, but we're running Lync server 2013 and not 2010. Is there anyway to fix this issue for Lync Server 2013?