Is this really Murder?

I have a friend that is doing a life sentence and has been in since 1980. He is in prison because him and his wife got into a fist fight and she ended up dying due to swelling on her brain. He says they were drinking, got into a knock down drag out fight and then made up and went to bed together. She later passed away and they say it was from a punch.... Now he is on parole and they have been dragging him and putting him off years at a time and most recently they put him off for three years to do a modality class. I was just wondering if this case would be a murder case or manslaughter?