As someone with an addic parent this is really terrifying.
My parent would behave the same way. Relapse, spiral, disappear and then rant either by text message or posting on Facebook.
The rants would become more and more unhinged. They'd make no sense grammatically and it would need to be deciphered.
The narrative they would create really scared us as kids. Because it would be completely untrue. But the way it was written and told we struggled to argue against it. Total lies told about almost every family member accusing innocent people of the worst things. Of domestic violence, sexual assault, faking pregnancies. You name it this person would accuse you of things so terrible that from the outside looking in you could understand why people would think surely no one would make this up.
Then the threats would come. False reports to police. Reports to social services.
They'd inevitably end up back in treatment. Then they'd come home and as children we were expected to welcome them and pat them on the back for being sober again.
The best thing for those children is to be nowhere near him if he's in active addiction. I can say that from experience. The adults in our lives should have protected us better and if Laura needs to share his behaviour publicly in order to be taken seriously and protect her children that's what she should do.
I no longer have a relationship with either parent. They're not together anymore and the addict parent is still continually posting lies and abuse about people on social media. The difference is now people know its just them spiralling.
I sincerely hope he gets the help he needs but unless he can acknowledge he has addiction issues and he wants to change then sadly it won't work. And as the child of an addict I'd much rather have grown up without that parent than being exposed to their behaviour.