Usually (and I am not stating it is a fact) a close friend saying that indicates the friend has been told or knows about some kind of physical violence having occurred before.
MY OPINION ONLY. Michael came home, Terri was in bed, he tried to have sex, she tried to fiegn sleep, he beat the crap out of her and threw her down the stairs, which caused a trauma the the vertebrae in the neck, partially cutting off air to the lungs, and Michael let her lay there and when she didn't die right away, he called her brother and gave him a BS story and asked him what to do.
Just one problem .. they lived in an apartment and I don't think they had stairs