will preface this with the caveat that it is a farming perspective - not an animal welfare perspective.
Where the animals are kept on a remote island with no human supervision, there will be an inevitable 'attrition' of stock through competition and natural events. I can not imagine that if the animals are kept there they are under constant supervision, so this sort of thing would be normal. Sheep die. Whether from accident, natural causes, disease or predation, it happens. A farmer might consider a certain loss rate acceptable from an economic viewpoint and would only intervene if it was impacting on the viability of the flock as a whole.
From an animal welfare perspective: I would be concerned that the animals a) did not have regular oversight and b) were exposed to whatever perverse activities the tenants of the accommodation wished to visit upon them ...
Not an answer, more a discussion ...
