(I had to look up "op-ed")
I think this is a case a of 6 of one, half a dozen of the other, maybe 5,7, though Mr Morgan always has the advantage because he is a teacher.
Did Ivor have an agenda in choosing that article? Yes, obviously he does.
Is it about a current event? That is difficult to say without seeing the article itself. It might be a feature or editorial in which case it is not. However, it might be about the publication of a report by Ofsted (insert the name of the education inspectorate for your locality here), or the results of a survey or study about teacher quality so in which case it would have been a current event. Maybe not the sort of event Mr Morgan had in mind but still a current event. If it is about, say, a school being closed done or put into special measures because of poor standards there is no doubt about its validity.
Did Mr Morgan have his own agenda in rejecting Ivor's choice of article? Almost certainly, especially if it was hitting too close to the truth for comfort. Even if he didn't then the choice of article, valid or not, certainly makes it look like he did.
Was Ivor's reply impertinent, or rude? Impertinent, probably; rude, if you want it to be. It certainly was not subtle and rather impolitic. It was, of course, obviously the payload that Ivor had in mind as soon as he saw the article.
Was Ivor right? Subsequent events suggest he probably was. Even if Ivor was impertinent a better, and more competent, would have dealt with it better. Maybe just ignored it and carried on, or come back with a suitable riposte. If it was not a valid as an article on current events explaining why it wasn't, possibly prefacing his response with something "Not really, as this comes from the Letters page....", or "That's as maybe but I do know the difference between a news story and the cryptic crossword clues...." might have been better way to deal with it.
Am I going to give Mr Morgan permission to use corporal punishment on Ivor? No. Not just no but NO WAY IN H3LL! I don't trust him and suspect his motives. Even it if Ivor was impertinent enough to warrant it this is about getting back at Ivor not discipline. That he is even thinking about using the Red Hornet for this rings alarm bells. I will tell Mr Morgan that request needs to come from someone higher up the food chain than he before I consider it. I am wondering why this request came from him, rather than some one higher up in the school, in the first place.
If I do get that request to use corporal punishment request from higher up the food chain, I am thinking of someone with 'headmaster' or synonym in their job title, I will probably allow it so long as Mr Morgan is not involved in the punishment.
Does Ivor get punished at home? If I have been waiting for a reason to punish him for this tendency then this is it. Otherwise he at least needs a warning about teacher-baiting especially if he had ended up being caned by the headmaster for it.
Slightly off topic but this is an opportunity to propagate this quotation:
ask an impertinent question, and you are on the way the to pertinent answer
---Jacob Bronowski,The Ascent of Man, final words of programme/chapter 4
(Of course in some situations that "pertinent answer" involves being told to take trousers and underpants down.)