I agree the idea of a right to be forgotten is a problem, don't really know how suitable and sufficient records will be maintained going forward, however there is an issue as occ health records are required to be held for for 40 years. I don't see HSE's desire for accurate records being over-ridden by GDPR personally, and until there is case law, it's going to be an ongoing issue.
to me the case is active till it's settled (especially accident records), and whilst there is the potential litigation for civil claim, the records will be required.
At InfoSec, there was a discussion about records management (backups) and right to be forgotten. Personally, i'd say it's technically unachieveable to have backups gone through and although someone will probably win a case somewhere, reasonableness and achieveability have to come in somewhere. An organisation has to have the ability to protect information from device failure, and whilst there's campaigners out there who will insist on everything getting rid, I am sure that there will be a backlash from those who are the sensible, and say that it is entirely impracticable to remove data from archives on a person by person, case by case basis.
Personally, as I suggested, by submitting the accurate details, then redacting the relevant information and storing redacted, I think there's a sensible compromise, (ala card details storage in line with PCI-DSS), however, some lawyers in london with money to burn will argue till they are blue in the face that black is white and the ones with the best arguement/lawyer etc will set a precident.
Till then people will follow the ICO guidance as far as they can and see what happens.
In terms of the original posting, the HR people will have the records of the person, and there has to be an accurate report to the HSE, as such, the process needs to be done and documented, then once completed someone can talk to lawyers, ICO, and HSE about "after may next year".