Piss-poor communication from all parties leads to a predictable result.
Hey dad, what do you mean "it's too good to sell"? Even if so, you can show your other students what your child is doing. Also, even if your child is a prodigy, you don't neglect your students like that. Their resentment was 100% earned, and it's all your fault.
"Well meaning" rival student, your heart might have been in the right place, but JFC, just talk to each other.
Montana is innocent. Given the "two years" spent learning how to make accessories, he would have been what, 13 or 14 at this point? Running away from the scary older people making a fuss is completely reasonable behavior from a child.