I was commenting about the general nature of such studies. Previous studies which have seperated out 'never drink' and 'former drinker' have shown opposite trends to the current study.
Also this study doesn't actually seperate out all 'former drinkers' from 'non drinkers', see their methodology.
". We reclassified non-drinkers as former drinkers if they had any record of drinking or a history of alcohol abuse in their entire clinical record entered on CPRD before study entry."
This will not capture a significant percentage of the former drinkers who are non drinkers. So contrary to your assertion, the current study did not truly separate out the two categories.