In your sample above with Lesa Marg and Susan, make sure you do not have any suppression on your detail rows. Suppressing will not impact the RT (it still evaluates the suppressed row) but will confuse you whne you are trying to validate the RT.
What is the exact next row after the one it skipped but should have counted?
If you can also do some testing by creating formula fields for each part of the RT formula and test to see if a certain part fails or not.
Make one formula for part 1:
{Audit_Trail.FieldName} = "Temp_Out" and {Audit_Trail.BeforeValue}= "1"
and {Audit_Trail.DateStamp} <= {?date}
and another for part 2:
(next({Audit_Trail.FieldName})<>{Audit_Trail.FieldName}
or
(next({Audit_Trail.FieldName})={Audit_Trail.FieldName} and
next({Audit_Trail.DateStamp})>{?date}))
Place then on the details section and you will see it evaluate True or False for each part and maybe you can figure out what part of the formula is screwing your count up.