Here's what I wound up doing:

(find unmatched entries)

FROM         A

WHERE     (NOT EXISTS

                  (SELECT     *

                    FROM          B

                    WHERE      A.Phone_Number = dbo.ccm.Phone_Number AND A.call_date = B.call_date AND 

                                                   A.Minutes BETWEEN dbo.ccm.minutes - 0.5 AND B.minutes...