The meal-offerings that are exceptions to the general acceptance of them when offered in error: a sin-offering, and a minhat kena'ot, the "jealousy" offering of the sotah-woman. With verses to establish why the sin-offering is necessarily different, while the sotah-offering is a little more complicated, and dependent also on some logic. But wait - there's another offering that cannot be offered with any error of intent: the Omer! Which permits new grain for use, so if it was not brought correctly, it wouldn't permit the new grain. With a parallel to the nazir. And what about a guilt-offering?