@Needspaceforlego @N0Tfunny others may have replied to this by now (I've not read to the end of page 24 yet).
Jane Russell KC is an English barrister. She is not registered at the faculty of advocates in Scotland. Nor is Naomi Cunningham who is also a barrister.
IANAL but my imperfect understanding this that employment law is one of the few areas where English barristers can work in Scotland. For other fields you need Scottish counsel in a Scottish court. There are some people working who have dual rights of audience with both the English and Scottish courts ie. they are both an advocate and a barrister.
My understanding (and this is based solely on a pub conversation with an advocate) is that it is easier to get audience rights in Scotland as an English barrister as they essentially grandfather you in after making sure you know the law whereas advocates going south are expected to do a whole pupillage.
Initial training pathways differ between the two nations too. My understanding (might be wrong)...
In Scotland it goes Law degree - > diploma of legal practice -> 2 year training contract -> registration as solicitor. Then people either go straight to the Bar (early entry) or they practice often in a specialist area for around 10-15 years and then go to the bar (mid career entry).
Bar training is a one year unpaid course, during which time they are taught advocacy skills and shadow practicing advocates "devilling". At the end of the year they get admitted as advocates, typically join one of the five stables and start building their practice.
In England you don't have to qualify to be a solicitor first , so can do the bar advocacy course straight out of university, then complete a competitive pupillage to get registered. Hopefully someone who understands the english system will come along to pad out my inadequate knowledge!
I'm not sure if there is anyone at the Scottish bar who has a lot of experience with GC cases which is why english counsel keep being used. I'd love to know which KC was sitting next to TT early on in this sitting as I have my suspicions from GC twitter that there is at least one prominent scottish silk interested in this area (and cynically in my experience all advocates will try build their practice/ earning capability by developing unique skills)....