Basically they are no longer harmonious, because they no longer have one direction, one perception and one goal. So it will be quite difficult for couples to continue their relationship well. Moreover, this couple received quite a large prize from their betting activities, with this money they were able to let go of their dependence on each other. and living alone is not a problem for him because he has enough money beside him. And dividing the money evenly is the best solution. but it was very unfortunate, just because of greed, instead of the money being able to provide happiness, the money they got only caused chaos which further complicated their relationship. And in the end, instead of them being able to enjoy the money for fun, the money is actually used up for court costs and to pay lawyers. Really stupid....
Just as you have rightly mentioned, greed is at play I both couples and there is high chances also that they already hard a stray relationship because if everything where to be good between the couples they should have been able to work things out within themselves and even if they will have a joint account for such an amount and split I within them later it could have been more mature.
Also from the story, we already know that the woman stated that the money used to purchase the ticke was her money and for sure she will definitely claim the money but at the end the man also will be legally entitled to some percents of that money being involved in the lottery process that leads to the winning.
While they sure had their own share of problems, I really think that if the amount of money is high enough, that can be more than enough to ruin a good relationship, after all if a person fund out that their partner wanted to keep all of that money for themselves and not share anything with them, then they have the right to be mad about it, however on this particular case it is going to be an uphill battle for the boyfriend as it seems that legally that money belongs only to her.