Most teachers seem to be at phase three, with its tint of greenness. It is often a slightly immature phase, not yet fully humanized and made ordinary.
This is OK if it happens within a tradition, where junior teachers work with guidance for senior teachers. If it happens on a “freelance” basis, it may be more questionable. In both cases, there are pitfalls. But in the second case, there is no-one to help you see it or get out of it. Of course, life will still help you see it, but it may happen in a more unpleasant way.
Adyashanti is a good example of a teacher at phase three. He is brilliant and clear, obviously tapped into the source. Yet, his teaching is also quite immature. It is the infant and child buddha stage. Still a buddha, but not yet matured.
Genpo Roshi is an example of a teacher at phase five. Mature, solid, thoroughly ordinary and human.