The Department of Education did not supply these books. In fact, it is highly likely that Friedman asked for them and they either refused to supply them or made it so complicated that if he went through the procedure, the kids would have the books about the time the term ended, if then.
New York City's school system is famous for their "rubber rooms" where teachers who commit REAL offenses such as child molestation go to spend the next ten years or so surfing the internet, reading, playing cards or whatever floats their boat at FULL SALARY while the district goes through the union mandated termination process.
It is funny how quickly they can turn on an award winning teacher who has done nothing worse than get his kids books outside of their payola process.
It doesn't matter. No teacher should sell anything directly to students. And I'm not just guessing about that. I've seen how such actions can lead to big problems. The teacher here didn't commit any crime that I can see. He just used poor judgment.
If I were his principal, I would have called him in for a little chat, and told him to refund the students' money. Case closed...except that I would have used some money from the school's discretionary funds to buy those books.
...and outside the Politically-Perverted loop.