When I read this first, I was astounded that Cryanair was missing the obvious retail opportunity.
They said that opening up the trollys would have been contrary to some law / regulation.
While this might have been the case in the days of 'duty-free' booze in the trolly a UK-Spain flight would have only duty-paid articles, n'est-ce-pas.
I've sipped champers on the ground, why would Cryanair passengers be denied their equivalent?