The easy thing to do is to put constant blame and responsibility on him. Obviously you cant be charitable and generous to everyone, especially in an age where scamming and finessing are celebrated as lifestyles to aspire toward. Clearly he was gullible and ignorant to how crafty scammers are.
But when you only join the conversation to point the finger at the person who got scammed and say "Welp that's what you get", you encourage the scammer to find their next victim.
Would you tell a rape victim "Welp that's what you get"? Would you tell someone who gets robbed at gunpoint "Welp that's what you get"? Would you tell a domestic violence victim "Welp that's what you get"?
We live in a world where we'd rather laugh and blame people for being victimized than punish the perpetrators.