Scotland’s most senior lawyer, who defended Alex Salmond at his sexual assault trial, has referred himself to the country’s legal watchdog after footage emerged that appears to show him identifying the complainants on a busy commuter train.

Last week a jury at the high court in Edinburgh found the former first minister not guilty of 12 sexual assaults, including one attempted rape. It also concluded that another charge of intent to rape was “not proven”, a Scottish legal formulation which stops short of a not guilty verdict but finds the accused innocent in the eyes of the law.

During and since the trial, the nine women who alleged assaults by the former Scottish National party leader have faced an onslaught of abuse online and on Sunday morning released a joint statement in which they described their “devastation” at the verdict. It is understood that they have been issued with personal alarms and have been offered home security checks by police.

Gordon Jackson QC was condemned for his “horrifying and completely unacceptable” comments after the Sunday Times reported he had been overheard making the remarks on board an Edinburgh to Glasgow train during the first week of the trial and that his conversation had been filmed by a passenger.

We thought that eventually people might think she’s a flake and not like her … All I need to do is put a smell on her

Jackson, who is dean of the Faculty of Advocates, appears to name two of the women who alleged sexual assaults by Salmond, in contravention of rules that protect the anonymity of complainers – as they are known in Scotland – in such cases.

Sandy Brindley, the chief executive of Rape Crisis Scotland, called for an investigation, saying: “Protecting the anonymity of all people who report sexual crimes is of critical importance and is one of few reassurances that can be offered as part of an otherwise daunting and intimidating process.

“For this to be undermined by such a senior lawyer in a public place in such a high-profile trial is horrifying and completely unacceptable. Jackson is dean of the Faculty of Advocates and we cannot see how this behaviour – caught on film – is in keeping with the Faculty of Advocates’ own guidance on conduct. There should be an immediate investigation.”

In the footage, Jackson can be heard saying: “This is hardly sexual … sex offenders register? Not for you. Inappropriate, arsehole, stupid … but sexual? Unfortunately, [names one complainer] and [names another complainer] say it’s sexual.”

Jackson also says of Salmond: “I don’t know much about senior politicians but he was quite an objectionable bully to work with in a way I don’t think Nicola [Sturgeon] is. I think he was a nasty person to work for … a nightmare to work for.”

Referring to one complainer, he says: “We thought that eventually people might think she’s a flake and not like her,” and goes on to discusses his defence tactics with another woman, saying: “All I need to do is put a smell on her.”

Brindley said: “One of the most chilling aspects of this is Jackson’s statement about his strategy for the cross-examination of one of the women in the trial: ‘All I need to do is put a smell on her.’ This statement alone confirms the fears of many who do not report for fear of what would be done to them in court. We need an urgent overhaul of how these cases are dealt with.”

In a statement released on Twitter, Jackson said: “I have decided that the proper course of action is to self-refer this matter to the Scottish Legal Complaints Commission, and that has been done. It will be for the Commission to consider this matter.

Salmond refuses to comment after making his statement. Photograph: Murdo MacLeod/The Guardian

“I also deeply regret the distress and difficulties which have been caused, but given the reference to the SLCC it would not be appropriate to comment further.”

A spokesperson for Salmond: “Mr Salmond … made a statement on the steps of the high court and said that he would make no further public comment on these matters until after the coronavirus crisis was over.”