Can a duty of care be umed if u feed a homless guy for 2 weeks and then take the food away whereby he dies?

Apart from the fact that this is a very unlikely scenario, presumably he is an adult of full age and understanding and is capable of looking after himself, unlike a child or a pet. There are plenty of organisations dedicated to helping the homeless, and I can't recall one of them being prosecuted for murder if they refuse someone another night's care on the grounds that the person is disruptive, threatening, violent, disobeying the rules, etc