When she was first minister and leader of the SNP, Nicola Sturgeon took a zero-tolerance approach to any allegation of wrong-doing, any whiff of scandal and any circumstance that made her leadership look weak.
Patrick Grady MP suspended his party membership following allegations about his conduct in a bar towards a colleague.
Michelle Thomson, then an MP, resigned the party whip after it was revealed she was part of a business venture that allegedly exploited people.
Although elected representatives who are under the media cosh are often seen to take the initiative by stepping aside, party business managers are always at hand to advise them what the leader thinks they should do.
Sturgeon’s ruling principle was clear. Anything that was a ‘bad look’ had to be dealt with whether or not there was actually anything of substance in allegations against colleagues.
If Humza Yousaf was treating Sturgeon’s arrest in the way in which she treated elected representatives against whom questions were being asked, then he would be suggesting to her that she withdraws from the party at this time.
Yesterday, after she was released without charge, she quite correctly reminded people that any citizen is innocent until proven guilty.
To ram home the point, the SNP MP Joanna Cherry, no political ally of the former first minister was careful to stress the same.
There are two issues here.
One is straightforward and involves legal process.
It will be for the Crown Office to come to conclusions on the business of whether key SNP officials spent money properly.
Anyone questioned as part of that process is innocent until a criminal court determines otherwise. That is not a point for debate.
The second issue is party management and reputational damage flowing from what one SNP MP has described as a ‘soap-opera’.
That second issue has nothing to do with the law and nothing to do with the presumption of innocence.
It is about the party leader being seen to be putting membership into the deep freeze until such time as there are definitive judgements made that make it safe for a colleague to resume their membership.
That’s the safety-first policy, the zero-tolerance approach beloved of Nicola Sturgeon and it is the approach that Yousaf should take not only to Sturgeon but to her husband Peter Murrell and the former SNP Treasurer Colin Beattie MSP.
Sturgeon herself will be only too conscious that the optics here are not good.
For one she continues to be a distraction. The ‘soap-opera’ has probably a few more performances left before it concludes and that means that Yousaf will continue to be hounded by questions.
Leaders have no choice but to put distance between themselves and colleagues with questions to answer.
The safety-first approach is about not looking weak further on down the line should the benevolence of today indict you as a leader of poor judgement if circumstances play out badly.
I would not be at all surprised if Nicola Sturgeon is giving serious consideration to resigning her membership until such time as we all know how the police probe will end.
She, perhaps uniquely, will be aware of the potential pitfalls for her successor.
It was once said of a former Labour leader that he was ‘a desiccated calculating machine’.
I have always thought that Sturgeon too was a politician who spent a lot of time calculating the consequences of events. She will know that it makes sense for her to be removed from Yousaf’s orbit.
Her statement yesterday was noticeable in one other regard. In so far as you can detect emotion from written words then you could sense a palpable sense of upset in her remarks.
That upset is understandable. Events of recent months have moved at such a pace that her reputation has taken a battering so much so that she cuts an almost lonely figure at Holyrood.
Even if events play well for her, a reputation earned over many years will never quite be the same again.
For that reason, I am sure she is looking beyond current issues to a life beyond politics, certainly a life beyond Holyrood.