Sometimes when students misinterpret your teaching cues it's because we could be clearer, and it happens to every teacher - that "when I said knee, I meant heel" moment. Sometimes students have so much going on in their minds that they simply don't hear you, and since students may not be willing to ask "could you repeat that one more time?" they interpret based on the room around them. They may go in the wrong direction or take a different variation, but they're trying. They may be in a place in their life or mental health where feeling "wrong" is enough to bring on tears.
If you're a yoga teacher and your room is confused, often you need to back it up to square one. Rather than getting frustrated or forging ahead with all sorts of interpretations in your room, take a deep breath and say, "let's try this again, back to the foundation. Sit on your bum. Extend your right leg..." Walk them calmly and clearly through the pose now that you've got their full attention.
If you're a student, take the same kind approach to yourself when you experience emotional overwhelm. Often we get into an anxious or sad state and say to ourselves, "stop it! get a grip on yourself!", but just like a teacher throwing out pose names without proper cues, how could anyone find their way there if they don't have clear instructions?
You may want to have a good shedding of that repressed energy, and it's okay to have a good cry. After one bad breakup, I told my teacher I was fine/happy without him/loving all the free time, only to have a cathartic sob in camel. It's okay. I often sit with students who are having a good cry and lend energetic support. No need to counsel, just sitting with someone who cares is enough for the moment. Quietly take a box of kleenex with you and offer.
As a student, if you are working to overcome this piece of experience in your life, be kind and walk yourself through the emotional overwhelm with the same gentle compassion you would teach a child to lace their shoes. Take one deep breath. Take a deeper breath. Refocus on your intention of calm. Listen to the teacher's voice. Feel your breath move deeper into your lungs. You are okay. Feel into your body. Rejoin this yoga pose with full attention. Get your full attention and take yourself through the steps to achieve equilibrium.
You are making good decisions. You are practicing a system that is proven to reduce emotional overwhelm and takes care of your body, heart and mind. Yoga is an excellent complement to any therapeutic course of action for chronic illness of body or mind, but everyone goes through difficult times and needs some guidance. Your yoga practice helps cultivate skillfulness around emotional needs, so you show up lighter and more focused in your life. What a gift you're giving yourself!