Looks to be a case of Penalisation as defined under Section 27 of the Safety Health and Welfare Act 2005 - Penalisation includes actions taken by the employer which are clearly to the detriment of the employee, including suspension, dismissal, demotion, or imposition of any discipline as a reprimand or financial penalty but also extends to activities which an employer might not consider to amount to penalisation, such as transfer of duties, change of location of place of work, change of working hours and coercion or intimidation. The employee will have to show that the penalisation complained of
arose as a result of the complaint made by them.
Redress is via the Rights commissioner though not EAT (can be appealed to Labour Court) within 6 months of the dismissal (can be extended under exceptional circumstances) so you might be outside the time now? You really should take legal advice.
A