The UK government would never bring RYR to task over alleged tax irregularities as they are far to large an employer both here and in Europe.
While they (UK HMRC) may gain by a win against RYR w.r.t. tax, any gain would only solicit adverse publicity against the incumbent government by them (RYR) either vastly reducing workforce, or shifting operations entirely out of the U.K. - government then accused of losing employee's their positions in a "well paid job", a whole trench of pilots/cabin crew/ground crew/admin staff etc., all possibly claiming unemployment benefit, associated employers who supply RYR would also suffer in similar ways.
I don't disagree neccessarily with the notion of RYR paying it's dues as per other employers, just can't see it happening for reasons stated above. Life unfortunately does not profer a level playing field to all in similar walks of life.