IMO,I don't think he started this with the money in mind. I 'think' they had a major fight and he was scared because she didn't get up. He called her dad in a panic..then 911 was called. I'm not sure at this point whether he thought she would pull through and he could convince her that he loved her (abuse victims are mentaly beaten down first..I know) or if he thought she would die. It could also be premeditated.
Next, she's in ER (it would be nice to have those records) now the doctors come to Michael and her family and start asking questions. Michael now has a clue to where to fight..