Rather than focusing on judging someone as abandoning the children, fight for what is "best" for the children. And that is access to both parents. Sometimes, fighting to have the other parent be responsible for and be with the children, rather than allowing them to abandon their children is the best thing to do...
"Access to," yes, CUSTODY is another matter.
I believe that children should be in the joint custody of any and all emotionally healthy parents.
LITB's wife would not be a good parent to these children right now in her current mindset, in my opinion, and her support system there in NM is not nearly as strong and stable as what LITB has here.
Just my opinion, but -- generally speaking -- people in active affairs do NOT make good parents.