Teachings/teachers which do not stress purification prior to or after awakening tend to be the ones in which you get the abuse scandals and the crazy-wisdom teachings in the worst cases. In better cases the teacher may just be a bit of an asshole at times, which is not the worst thing in the world, and to be honest, who isn’t an asshole at times? We are all human, after all (apparently), but it is a matter of degrees. With sattva, the chances of being rude, ignorant, abrasive and uncompassionate vastly decreases, but of course can occur from time to time, usually without the teacher intending to be offensive. When tamas and rajas predominate in a teacher, the distortion will be apparent in the teaching and its energy, and the teacher will likely act out their egoic vasanas from time to time and cause suffering to themselves and others accordingly.
You can often sense the energy of a particular teaching from energy the group of long-term seekers who are keyed into that particular teaching. Some teachers attract tamasic seekers, others attract rajasic ones, and others sattvic ones. Of course it doesn’t always work exactly like this – these are just general rules.
Take in these teachings, and see if they are true for you.
The above text was taken from a longer article which explains this in more detail.