So if Stern manages to delay this for five years, he should automatically get custody? Children are more resilient than we give them credit for.
I pray this does not happen. But if it does, I say yes. As long as he is not abusive, that is too long with a parent. Biology does not matter as much to the child as the people she needs and loves as parents. Children are resilient and that is good for when they HAVE to be (a parent dying, for instance), but that does not mean that decisions made for children need not be in the absolute best interest of the CHILD. A child should never be taken from his parent(s) who has been raising him unless there is great negligence or abuse. Who cares who ACTUALLY donated the sperm, after a couple of years of loving parenting?
However, in this case, you have an apparent bio-father fighting to see his child from pregnancy on, and another man apparently using international trickery to keep said child away from him. Yes, the child's mother was complicit, but was she in sound mind? I think that is the legal argument right there. I believe that even 6 months with one parent will be hard for the baby to get over, but at least she is so young that it will be in her best interest to not be with a person who connived custody and possibly contributed to the death of her closest relatives.