the diviners have lying visions and publish empty dreams and voice misleading nonsense, naturally the people stray like sheep; they wander because they have no shepherd (Zechariah 9:1-10:2)
But I would be truly dishonest if I did not note how difficult it can be - has been - for anyone in a position to teach or explain, even the simplest of truths sometimes. As a father, it is always a challenge to square what I teach my children as true and how I live that truth, or not, in my actions and decisions. To a lesser degree, the same dilemma can come up in the classroom as well.
Such a challenge is also a blessing, of course, because it forces me to consider things very carefully, particularly when it involves my children. It takes a remarkable leap to tell children one thing and then act or decide contrary to that, particularly, one's own. I used to think that hypocrisy was an easy concept to explain, until my kids started getting older. :-)
So, there are no simplistic judgements on specific persons who may, at one time or another, be guilty of false teaching or leadership. The temptation can be incredible, but so are the consequences, which are inescapable. Sadly, the consequences include collateral damage. Thankfully, God's grace is always sufficient, and his mercy is ever available to the sincere, should they come around and are willing, as with post-operative patients, to get down to the hard but necessary work of recovery.