I am new here but I live in the West of Ireland.
The issue of Topcover appears to be that it's provided by the Irish Air Corps using fixed wing. I understand that this stems from not wanting to tie up another Helicopter & leave cover thin for the rest of the Island. Plus a fixed wing will have a longer range, & loiter ability.
There is probably some politics here. The IAC used to provide SAR. They wanted to continue but it would of needed a big investment, so the government decided to contract it out.
An illustration of the thin resources is it took 5 hours to get a fixed wing airborne after the incident. Another "unspoken" aspect is whether the other helicopter, on route back from rescuing a casualty, passed close to the site as there were reports of a strobe being seen.