This UK case might have persuasive relevance in the Republic of Ireland. Readers may recall that in February 2014 the UK Ministry of Justice was held liable for an injury, caused by a prisoner, to a catering manager at a prison kitchen. The then complainant, Ms Cox, was in Crown service and therefore was not actually an employee. Neither was the negligent prisoner, although prisoners in the kitchen receive nominal wages. 

The England & Wales Court of Appeal looked at previous case law in this area and concluded that the prison service was a quasi employer and that the prison/prisoner relationship might even be more controlled than that of employer/employee:

"Far from there being mutuality or consent in the relationships... there was there and is here an element of compulsion in engaging in the activity directed by the 'quasi-employer'."

The UK Supreme Court has now upheld that decision and has rejected an appeal by the MoJ. The Supreme Court has, in effect, applied the doctrine of vicarious liability to the modern workplace, where non-employees, intrinsically linked to the functions of the employer, operate on behalf of employers or deliver their services, in this case, "working as an integral part of the operation of the prison and for its benefit." 

Lord Reed, giving the lead (unanimous) judgement found little wriggle-room for service providers using non-employees in the delivery of services:

"The prison service carries on activities in furtherance of its aims. The fact that those aims are not commercially motivated, but serve the public interest, is no bar to the imposition of vicarious liability. Prisoners working in the prison kitchens, such as Mr Inder, are integrated into the operation of the prison, so that the activities assigned to them by the prison service form an integral part of the activities which it carries on in the furtherance of its aims: in particular, the activity of providing meals for prisoners. They are placed by the prison service in a position where there is a risk that they may commit a variety of negligent acts within the field of activities assigned to them. That is recognised by the health and safety training which they receive. Furthermore, they work under the direction of prison staff. Mrs Cox was injured as a result of negligence by Mr Inder in carrying on the activities assigned to him. The prison service is therefore vicariously liable to her."
https://www.supremecourt.uk/cases/docs/uksc-2014-0089-judgment.pdf 

The Court's summary of its decision is available on YouTube:
https://www.youtube.com/watch?v=2BXhXHr0w0c