Other visitors to Ireland are not entitled to avail of free or subsidised public health services except in cases of hardship. In general, if they have to use health services, they must pay the full economic cost of those services.
https://www.citizensinformation.ie/en/health/health_system/health_services_and_visitors_to_ireland.html
I'm betting they billed his insurance and that he had international coverage, I always do when I travel