1. In an ensemble where material is below their ability level causing boredom and even more chances to act out
2. With a teacher most likely that has less experience and is developing classroom management skills
3. And you are communicating to the students in that lower band that they are a dumping ground where “kids who don’t take care of their business” end up.
It’s a tough decision to make but should be done in a case by case basis. Just be mindful that you just aren’t passing off the “problem” to an ensemble that already comes with its own set of challenges, to “prove a point” to that kid.