I agree with Lou's assessment of what your BF's ex is doing. I think she's just trying to milk out the last bit of money she can. The cheapest and least painful route may be to just pay her off in exchange for dropping all charges.
I still think this is a great opportunity for YOU! What better time to step up and show your committment to the R and bring out the issues that are keeping you BF trapped in his resentment and emotional distance. I think this could be he kind of breakthrough that can do more than all the books you have read over thepast 5 years! He is 50% of the equation, plus all you haveto do is get him to agree to talk about it in counseling, so your completely off the hook.
See, there are goods things that do happen to good people! Karma always seems to work out justly.