The HSE have made some basic mistakes.
1) Lab Test criteria
Since Feb 24 the WHO have recommended expanded testing based on symptoms not just travel history/close contact with known cases, with the following recommendation:
Immediately expand surveillance to detect COVID-19 transmission chains, by testing all patients with atypical pneumonias, conducting screening in some patients with upper respiratory illnesses and/or recent COVID-19 exposure, and adding testing for the COVID-19 virus to existing surveillance systems (e.g. systems for influenza-like-illness and SARI)
The HSE retained very restrictive criteria. The expanded criteria might have helped with the Cork case, due to the long delay between onset of symptoms and isolation. The USA/CDC have allowed expanded testing from Feb 26, due to both medical and media pressure.
2) Travellers returning from Italy
The USA, UK and New Zealand all recommend self-quarantine for 14 days for travellers returning from or transiting through Northern Italy (or Italy). In Ireland the advice is "if you feel well, then keep to your normal routine". The HSE are ignoring multiple documented cases of transmission with no symptoms or only mild/non-specific symptoms. The HSE model of how the disease works doesn't match with reality. Many universities in the USA require 14-day self-isolation of returning students/faculty not just from CDC Level 3 (e.g. Italy, S. Korea) but also Level 2 (e.g. Japan).
Best practice is Singapore and Taiwan, but that bar is impossibly high for the HSE/Irish government. Ireland should at least be trying to match WHO and USA/UK guidelines.