How do you guarantee that? If it's just a matter of asking consent, that's probably illegal. If the person died from other causes (illness, accidents, old age etc.), I'd question whether it's safe (illness) or palatable (old age) to eat that meat.
I have a hard time believing that the foot was entirely unaffected by the injury ... it's whatever if it's your own limb, but I wouldn't eat someone else's limb that was amputated due to injury.
He did state that the limb was healthy, and he could have kept it, but it wasn't structurally sound enough to take his weight. Hence there wouldn't have been gangrene or anything like that.
Gangrene's kinda nasty, I agree. Come to think of it, it would be like eating severely spoiled meat. There's a reason doctors cut that stuff out of you.
Just sign up to be a meat donor like you sign up to be an organ donor. if you were healthy enough to have your organs harvested at death, you were healthy enough to eat (probably idk).
It would probably be enough fitting: If you work in a mortuary, an you have cases of young people that consented to donate their dead body to whatever. I mean they are dead anyway. And they get cremated. So know harm in taking the calf.