No, False employment is ALWAYS the fault of the EmployER, therefore, it is Ryanair who is resonsible for paying the owed taxes and social contributions.
A clear as water according to EU legislation.
The Employee is ALWAYS the victim and will more than probably even get a large compensation due to being forced to accept an illegal contract and work under illegal work conditions. And yes, if a company obliges you to sign a certain type of illegal copy, or not hire you at all, this is considered as a forced contract.
So no exuses claiming that the employee could also not have accepted the contract...