Why did she use him for money ?

You could explain that you said what you did because you care, also I would suggest explaining that often there is people out there that swindle money out of others. She was probably desperate for money for her family or she could have just wanted money. Your friend sounds like he has a very sweet heart, be there for him and help him through it. There isn't much chance of getting any of the money back but you can be there for him and explain you care about him