There's a lot of stuff I can't understand Ryanair getting away with (charging for online check in? Do I have an option?) But what really beggars belief is that self employed 'employees' are told which firm of accountants to use.
If I worked for RYR and they insisted I was 'self employed', I'd want to set myself up as a Cayman Islands based company, paid into a Leichstenstein bank account with accountants based in Dubai administering my day to day affairs and my Channel Islands based pension.