Wow, I would be saying no if your husband is a RA he should know this boy has to help himself and from what your saying he is not. I am not quite sure what your husband thinks he can do to help him. I am the mother of 2 addicts and also the wife of one.
I suggest any and all valuables be locked up. I really don't know what more to add seems your husbands mind is made up. Read the sticky's at the top of the forum I hope your husband is very strong in his own recovery.