Let's remember that Jason was nude and in his bedroom. I have a difficult time imagining him arguing with anyone, other than his wife, in the nude. Therefore , if this began with an argument, in my opinion, that argument was between husband and wife in the privacy of their bedroom. In that case, TM came rushing in.
There is a pathology in this family however that is apparent in their actions after the murder and to this day. They seem to believe in their own entitlement. Their daughter married a man that she soon discovered she did not love. But, even considering the short period of marriage, she wanted that man's children and the lifestyle his hard work provided her. Her family thought she should have both.
The unbelievably callous "operation" that swung into place immediately...that included the Mother, Father, Uncle, Aunt...to cover up and collect from the man they killed those very things they coveted...makes the whole family seem like heartless grifters. If it is true that they tried to have a cremation to cover their crime, and further their access to the children and the money, that is beyond the pale.
Their actions show that Jason must have meant nothing to them. The Martens had no interest in his family, in the grief of those who loved him. They were instead immediately organized to rob him of everything he worked for and those children he loved. This is so obscene...it puts the lot of them in a different perspective.
So in that case...maybe Daddy and Mommy Marten came flying down to Molly's defense, furious that the money and kids would be removed from their grasp. Maybe TM did throw the first punch and Molly joined in, beating with the brick, and the mother, hearing the commotion, got her husband a bat from the garage and then they didn't stop till they knew Jason was dead.
After, Jason was taken away, they swung into action...moving large sums of money, trying to arrange a cremation, and filing to keep the kids.
The more we learn about this family, the more grasping and monstrous they seem to me. I can only imagine the heartache of the Corbett family, knowing what these people are truly like and fearing for those children!
I think a jury will see the Martens much as I do. They keep "revealing" their attitudes. This stunt with the removal of the furniture. The attorney's lies about "kids taken in the middle of the night." The "drama" of the Facebook page compared to the inhumane lack of any feeling shown for the man they killed...just a stunning exposure of their "entitlement" and emotional apathy toward anybody other than themselves.
My opinion only.