I dont think he has underestimated her at all. He or someone advising him has got the full measure of her. There is no way for him to exit without her reacting in this way. BW is just a name she can put to a belief she had already. Before then she was dismissing the collaborative agreement, alienating the children, abusing him on SM and selling stories and interviews.I agree. As much as we say he underestimated her, she underestimated him completely. She’s lost the control she had and this is what we’re seeing in her behaviour. She’s raging he dared leave and how he’s handling it all now legally and properly. Each time she tries to out-do him, he steps up. There’s the contentious photo release (I’m of the mind he had enough and wanted to let her know he wasn’t coming back) then when she’s going off about him being a dead beat dad and the cocaine use he gets 50/50 custody and Christmas Day. She knew a decision was coming and she tried to throw him under the bus before she lost. She wanted 80/20 custody.
These are the ramblings of a narc losing control.
She wants him to react to her. Nothing would make her happier than to have him ring up and yell at her so she can cry and use her baby voice. But there aren’t many more lows for her to sink other abuse.