Personaly I think there were Zen and Advaita masters who were enlightened, or at least Stream-Enterers. If you think of guys like Hui Neng, Huang Po, Dogen, or Shankara, Ramana Maharshi, Sri Nisargadatta: can one reasonably think they were putthujanas???
On the other hand, they propounded views that might be considered wrong according to the Buddha teaching. For example, Huang Po speaks of the One Mind, beyond which nothing exists, or, as well known, Shankara speaks of the Self.
So there are 3 options it seems:
1) One can be partially or totally enlightened with wrong view(!)
2) they had right view but expressed it in a different manner than the Buddha.
3) they were Putthujana, i.e, non enlightened at all