One of the Users 'Last Name' and 'Email Address' are changed and updated in the Active Directory. The updated name can also be seen in 'Manage User Properties' link in the Central Admin.
But when I tried to check permissions for the user using 'Check Permissions' link in Site Permissions, I still see the old name. I did a Incremental Profile sync. Also, Important point to note is that this name change happened in Nov,2015 and still the SharePoint People Picker control shows Old name.