Intentional trolling. My mom is sharp and well aware of internet scams. (Well, she was 15ish years ago, when she did this. She’s slowed down a bit of late, but she’s careful to check with one of us to make sure things are on the up-and-up.) She had a blast messing with him.
My Silent Generation mom kept one of these guys on the phone for an hour before telling him she didn’t have a computer. Oh, the language he used afterwards!