It’s probably a sign of my past as a chief-sub that my first reaction to the news that Angus MacNeil had a barney with his chief whip Brendan O’Hara and called him a “small wee man” was that Mr MacNeil’s insult was tautological and that removing either “small” or “wee” could have saved space in the sentence and made the insult tighter. But that may not be the main point.

The main point is that Mr MacNeil is alleged to have broken the rules of the SNP as stated in the party’s constitution, specifically Article 4.4: “Membership shall cease when the member dies; intimates his or her resignation either to his or her branch or to the national executive committee, or publicly; ceases to pay the membership subscription; is expelled; or in other cases as set out in the membership rules.” The semi-colons in that paragraph are wrong by the way; they should be commas (chief-sub again).

The problem for Mr MacNeil is that, according to an SNP spokesman, by refusing to rejoin the parliamentary group after having the whip removed over the “small wee man” row, Mr MacNeil was in breach of the code of conduct, which enforces the principles of the constitution and which every member must obey. The code states “membership ceases when a member intimates their resignation to the party or publicly resigns” and the SNP spokesman claimed Mr MacNeil had broken this part of the code.

But – and this is probably a sign of my past as a law student – the details of the rules explicitly contradict what the SNP spokesman said. Article 4.4 states membership “shall cease when the member intimates his resignation publicly” and it’s clear from Article 4.1 that it means membership of the party. It follows therefore that the code of conduct must be read in the same way – in other words, when it says membership ceases if someone resigns publicly, it means membership of the party, not a parliamentary group.

These may seem like trivial details compared to the bigger picture, which is that the relationship between Mr MacNeil and the SNP is over, but it matters for several reasons. First of all, SNP sources are telling The Herald that Mr MacNeil is in clear breach of the party's rules on public resignations when it’s clear he isn’t, and a party that has a lot of ground to make up on its public reputation should be more careful about saying things which aren’t true. That’s the first point.

The second point is the SNP’s behaviour over Mr MacNeil appears to demonstrate that it’s learned nothing about its controlling tendencies. All parties do it to some extent but the SNP has been a particularly enthusiastic and (until recently) effective proponent of the total-control strategy. Article 4.3 of its constitution states “members shall abide by the policy and direction of the party” which appears to mean members must agree with whatever the leadership says, and Mr MacNeil clearly hasn’t done that on independence and so must be punished.

But this is pretty retrogressive stuff from the party, particularly I would have thought on an issue like Scottish independence which – like Brexit – needs to be discussed and tested as widely as possible, including within the SNP. Mr MacNeil said it would be strange to be thrown out of the party for agitating for independence and he has a point: he disagrees with the direction of the SNP under Humza Yousaf (whatever that direction may be) but the idea that all his colleagues agree with it is an illusion, enforced by Article 4.3.

Party rules such as this – that everyone must agree with the boss – have two further effects, the first of which is to encourage and perpetuate the paraphernalia and nonsense that goes with chief whips. Mr MacNeil tweeted after the altercation with Mr O’Hara that we should always stand up to bullies and while we don’t know exactly what went on between the two men, we can say that the chief-whip model is expressly based on the idea of one man (usually a man) forcing another to do something against his will. Mr MacNeil said school teaches us we have to stand up to that kind of thing and I couldn’t agree more.

The second effect of overly-controlling party rules, and it’s the one that makes me saddest in a way, is that they discourage a certain type of politician that the system needs if it’s not to atrophy completely, by which I mean the iconoclast, the rebel, the guy that doesn’t always stick to the rules. I’m not saying Mr MacNeil is necessarily the best example of this category – I find some of his remarks too ill-thought-through to be convincing – but every organisation needs a mix of the obedient and the disobedient; the yes-men (who often end up as managers and get things done) and the rebels (who mix it up and can take things in unexpected directions).

I realise this is all ending up as something of a unionist herogram for someone who, politically, is on the other side of the room from me, and I also realise the mischievous side of me is writing it partly because I relish the sight of the SNP in trouble. But I do also wonder if the stramash demonstrates that the SNP still doesn’t really get where the independence movement needs to go. From 2014 onwards, it was an outwardly left-of-centre movement led by the SNP and pretty much consumed and controlled by the SNP. But increasingly nationalists are realising that what’s needed is a much more pluralistic campaign less associated with any one party, particularly a damaged one like the SNP.

The fact the leadership of the party is still trying to crack down on Mr MacNeil regardless would seem to suggest the message isn’t getting through; in fact, it looks as if he’s going to be expelled from the party for good.

But for a party like the SNP to say there’s no way back for an outspoken politician like Mr MacNeil is a bad sign. Leaders of a party that’s going up in the polls may think it’s because they don’t tolerate dissenters, but a party that’s going down in the polls is making a mistake if it believes cracking down on the dissenters even harder will reverse the slide.

So a bit of advice for the SNP if I may (just a small wee bit): if you want to get more people to agree with you, tolerate the people who don’t.