Ekspresi tipe non-boolean yang ditentukan dalam konteks di mana kondisi diharapkan, di dekat 'END'

Saya cukup yakin jawaban lain mengabaikan kasus:

WHERE 
(Table.Field = stuff)
AND
(Table.Field2 = otherstuff)
AND
(Table2.Field3 = someotherstuff)
AND
(
    (@param1 = 0 and Table.Field IS NULL)
    OR
    (@param1 = 1 and NOT Table.Field2 IS NULL)
    OR
    (@param1 <> 0 AND @param1 <> 1) -- isn't this needed?
)