[US] Elderly neighbor currently being scammed, how do I help?

An 80-year-old man in California was scammed into sending $20,000 via wire transfer after receiving calls from impersonators claiming to be from 'Computer security,' his bank, and 'The Federal Reserve.' The victim, who lives alone, is being confronted when advised to cancel the transfer, and the poster seeks guidance on how to help without damaging their relationship.