Yes, we try to remember the Kalama Sutta. How do we judge the level of practice of a student? Since we focus on Compassion and Wisdom as very important, checking the level of how those are manifesting in their life can be useful. Compassion and Wisdom, and how it's influencing how they live in the world. In their Morality, in their understanding of Cause and Effect and the Four Noble Truths. Then we can see that their practice is working. We certainly don't judge the level of practice simply through a person's power of concentration but how they are walking the Noble Eightfold Path in their life.
Another teacher? The Kalama Sutta here. What they teach, does it lead to harm and ill on the level of morality or not? Or does it lead to benefit and happiness if practiced? Since we focus on the Four Noble Truths as the practice, we will judge another teacher by their understanding of the Four Noble Truths and the Noble Eightfold Path, especially Right Understanding and Right Intention. If they can give us some hints on, or say some useful things about the Four Noble Truths, the Eightfold Path, dealing with the hindrances, etc. (the core Buddhist practice), then we will usually judge a teacher on that understanding.