Why is the disabled SA user listed as logged in?

I was looking for the last time users have been logged into the system and saw SA as being used. Strange is that SA is disabled by default and not used on our systems. How is that possible, what am I missing? The query used to list users: SELECT login_name [Login] , MAX(login_time) AS [Last Login Time] FROM sys.dm_exec_sessions GROUP BY login_name; The result with SA listed as disabled and logged in: