Your DH is bring extremely foolish.
Firstly, he needs to take to his accountant about doing this is the most tax efficient way and ensuring it's properly taxed and accounted for. A smart accountant will tell him he's daft but can't stop him.
If he still insists, he should have friend sign a properly documented loan agreement.
I used to work in debt recovery. I estimate about 25% of people get into difficulty through no fault of their own - job lodes, bereavement, illness etc.
The remainder do so because of stupidity, bad choices and overspending. They don't change and repeat the same patterns continuously.
Mainstream banks want to lend money. It's how they make money. If they won't let to his friend, there's a damn good reason.
IME, it's the decent genuine people and helpful (albeit naive) friends and family that get stung. They are the people who will help clear debt, make up arrears and have signed guarantees.
I would bet everything on your husband never receiving a penny. He is just replacing the poor idiot who lent the first time and will require another idiot to take out his loan if the friend can find one.
There's lots of other ways to help, pointing him to stepchange, helping with loan application, helping with budgeting etc.
The only way he should five his fridnd this money is if he considers it a gift and it's gone. The probability of getting is back is so low.