Why is it that mothers have no recourse when it comes to domestic violence and mistreated sons?

My son has a domestic violence charge against him due to the fact that he is diabetic and got left at home for 5 hrs with no food by his domestic partner while babysitting their daughter, When she got home she knew his sugar would be bottomed out and he was trying to leave to go get food because he could tell his sugar was going to bottom out she jumped on top of him in the drivers seat only to get her clothes that she had just bought to go out that night. He then pushed her off of him because he needed food and an off duty cop was standing there and he went to jail. She got an order of protection only so she could peacefully have a new boyfriend and come to find out she was cheating on him for years. Now I know there are legitimate problems out there when it comes to domestic violence however I do think it should be evaluated on a case by case basis. Because If she had just been honest and broke it off and told him she had someone else and he didn't have to catch her in their bed maybe he wouldn't have been put in the position he was put in. And while I know its his responsibility to control his anger she has lived with him 5 yrs and is very aware of low blood sugar symptoms. She set him up and 10,000 later she ruined his life I don't get to see my grandchildren or my son because he was so depressed after she had him fired he left. He is 29 and homeless at this point because she got the home, I talk to him on the phone but I don't know where he is at. It is very depressing to lose your grandchildren and cant see your son while she goes on with her happy life. His daughter was what he lived for. I am so sad and depressed HELP I miss my family