Raitanator kirjoitti:"You say that if a layman attains arahantship he must either enter the Order that very day or die and attainparinibbàna. Yet if he is unable to find a robe and bowl and preceptor then that exalted condition of arahantship is a waste, for destruction of life is involved in it."
"The fault does not lie with arahantship but with the state of a layman, because it is too weak to support arahantship. Just as, O king, although food protects the life of beings it will take away the life of one whose digestion is weak; so too, if a layman attains arahantship he must, because of the weakness of that condition, enter the Order that very day or die."
The Milindapanha, which is almost as old as the [rest of (Burmese ed.)] Pali Canon above implies that lay people do/did attain enlightenment. It is just that they all ordained or died within 7 days or less.
Kaikkea ne keksiikin.