So the life insurance policy, Kathleen's estate, the massive debt Mike accumulated, and finally being able to lead his much desired gay lifestyle, were the sole motives to letting Kathleen bleed out before ever dialling 911.
Problem was, Mike used the lame 'fell down the stairs' excuse to explain her accident and death, let her bleed out long before dialing 911, tried to clean up some of his mistakes, got rid of evidence, and lied about being outside by the pool. Mike thought her death was simply going to be ruled accidental (just like in Germany) because he's smarter than everyone else and also a witty and clever author (again, in his own mind), and then he would collect all the money and live happily ever after.
Only problem was, Mike had to spend most of the estate to pay for his shitty legal defense which cost almost $1 MILLION. Plus his two sons from the first marriage (they weren't Kathleen's biological kids) were in massive credit card debt just like Mike, and their biological mom was no help.