I think if he has free grazing, and you make it clear it's his for a few years yet, he will be happy with that, if he's refused money once, offering him anything else may still embarrass him.
Couple of years ago I borrowed a zwartble tup, as I went to leave, owner said, 'don't worry if he dies' (look of horror on my face), then she went on to say he was insured. He was returned safely :- ).
Free grazing is valuable, as is keeping well in with the landowner.