Haven't seen the movie....but remember many court cases in the past where this situation had come up...many, many times, the biological father won the right to get the child back....It was on the news, and the child was screaming and crying, being dragged from the adoptive mother's arms!....It was heartbreaking to watch it...
Here in Duval County, every effort is made to contact the biological parents, 3-6 months, even posting it in the newspapers before allowing the adoption of the child/children.
In my case, both parents were found and both signed away their parental rights....My boys' birth certificates have my name as the "natural mother" on them.....
As far as the "father" not knowing the woman was pregnant, and she giving the child up for adoption...if every effort was made to find out who and where the father is/was...and no responses....then I feel the adoptive parents should have "full rights'....However, the law doesn't always work in their favor!....Many people who are childless and unable to have children, are "wary" of adoptions, knowing that in some cases, the child could go back to the natural parent(s).
I feel sorry for the real father....but he should be aware that his child is now adopted and in a good home....being allowed visitation rights...but not full custody of the child....when the child get older, then perhaps the child will make a decision who to live with, as long as the child has been told what had happened and why they were adopted.
My 3 adopted boys have been with me for 10 years....before I would have them taken away...I would go to the Supreme Court and fight it!....The natural father gets released from prison next year, 2012....I will not allow any visitation from him! When the boys reach legal age, then it will be their decision, if any, to have contact with their real father/mother.