I'm not sure I'm following. Ronald knew what she was doing; knew who she was with, knew everything but where she was. When she returned home, they were up all night "talking" according to TN, and she was so so tired (according to TN and Misty). Ronald KNEW from the jump that Misty had been out partying that weekend, came home still jacked up (you don't just float gently down to the ground after binging). Ronald knew when he left at whatever time it was he left that he was leaving his children with someone who had only just gotten back from a weekend party. Ronald KNEW.
The question for me is: Why did Ronald want her back so badly, and why would Misty agree to come back?
I highly suspect the incident/accident that took place that afternoon/early evening is what served as a catalyst for the unwanted reconciliation...JMO