Its an extrapolation:
https://nipsa.org.uk/publications/AR2017.pdf
Central Whitley
M McKeown
Assistant Trade Union Side Secretary
See page 64 at B1
It talks to LGBT issues and a survey in development that then informs policy in 2018 which becomes the published Trans in Workplace Policy published in 2020 and still in force.
'acknowledging the continuing need for Trade Union Side to progress related issues within the Central Whitley context. It was also agreed that further policy work would neeed to be done to further support LGBT staff and in particular those transitioning in the workplace'
My read - if McKeown is the Trade Union Side for Central Whitley and was progressing matters relating to a LGBT survey and doing further policy work to support those transitioning the workplace in 2017 that led to an illegal policy that means women don't have single sex toilets or changing rooms - then he needs to declare that conflict of interest.
If it wasn't just a random vote but direct input on shaping policy then it should be put before the Tribunal for EJ Sturgeon to decide on whehter he is impartial.
If he didn't then the question needs to be put to the Panel.