Yes, right now it is protecting teachers.
There was a judgment on December 20, 2023, by the Ontario court in R. v. Bender. It was an elementary school teacher who was teaching grade 3. He was teaching a difficult class of students with special needs. Unfortunately, what happened was that he was charged in December 2020, and it took three years before the judgment came out. The conclusion was that his actions were justified under section 43.
So yes, it is doing the job, but as I said before, it was written in 1892. I think the problem with section 43 is “force by way of correction”. That's why our amendment is really precise about safety.