Ok, but suppose he has evidence that the house in Henley was bought as an investment property?It doesn’t matter what they were planning together that now isn’t going to happen. Her releasing this letter is all to do with which country has jurisdiction on dealing with the custodial arrangements for the children, proving he was planning future in the UK and it wasn’t temporary.
The children were last habitually resident in the UK with both parents, he took them temporarily back to the US while she was working and then filed for divorce and refused for her to let the children leave the US. So he is in breach of The Hague Convention for wrongful retention in the US.
She’s going to have 17 more years dealing with this asshole.
As a hypothetical...
I agree he has been rash and legally is in a weak position due to her sensibly filing the abduction case.
I'm undecided if he was vain or greedy (he was apparently working in New York) not to work out that if he was going to do this he needed to be in Miami (or where ever their house is) so that one court would deal with the Divorce and the Child Custody issues - and in terms of the Hague convention was a residence the children had lived at.
Now he's stuck in a limbo with the New York courts deciding child custody and the Florida courts the divorce... with the English courts waiting in the wings.
So unless he heard her, over the ring doorbell, confess to poisoning him with arsenic over a period of time...
he, or his lawyers, better come up with a good story.