Is there a statute of limitations on a divorce decree in Nevada?

I have a very interesting situation going in with my family right now. My mother has married a man that none of us in the family liked. He is so shady and lies every other word. Anyways, they have been married for 5 years now, and his past has finally caught up with him. Child support enforcement has sent him a notice of arrears of 40K. His ex-wife is also suing him for spousal support, and child support that he never paid. I didn't believe him at first, but I read the complaint and the total amout combined she is asking for is over 700,000 dollars. The catch is, this man isn't worth a dime. According to his tax forms dug up by his attorney, he hast had a job since 1972. And the only amount of money he has, is an inheritance from his mother. Co-incidentally, his mother just passed and he claims he will be getting around 800,000 dollars. The only reason I, and the rest of my family are concerned about his financial status is because my mother has foolishly let him handle her finances, and he has spent her down to nothing and 100K in debt. This dovorce decree is 14 years old, and apparently, his ex-wife lied about his income years ago. SO, he thinks everything is going to just go away because she lied about his income, but I can't see child support going away. Is it possible to enforce such an inflated request so many years later. I assume that these amounts will just be adjusted to some sort of statute of limitations or something. Anyone have any insight of this situation?