Adoptive Couple v. Baby Girl.

Here's a case the Supreme Court accepted for review last month that's about a father who gave up his parental rights via text message:

Facts of the Case
When the biological mother of Baby Girl became pregnant she did not live with the father and the father did not support the mother financially. The mother sent the father a text message asking if he would rather pay child support or relinquish his parental rights. He sent a text back, saying that he would relinquish his rights, though he later testified that he thought he was relinquishing his rights only to the mother. The biological father was a registered member of the Cherokee Nation. The biological mother attempted to verify this status, but spelled the father’s name wrong and misrepresented his birthday in the request, so the Nation could not locate the father’s registration. The mother listed Baby Girl’s ethnicity as “Hispanic” instead of “Native American” on the birth certificate. The mother decided to put Baby Girl up for adoption because she had two other children that she struggled to support.

Adoptive Couple, who resided in South Carolina, began adoption proceedings in that state. The Cherokee Nation finally identified the father as a registered member and filed a notice of intervention, stating that Baby Girl was an “Indian Child” under the Federal Indian Child Welfare Act (ICWA). The father stated that he did not consent to the adoption and would seek custody of Baby Girl. After trial, the family court denied Adoptive Couple’s petition for adoption and granted custody to the biological father. The court held that the biological father was a “parent” under the ICWA because of his paternity and pursuit of custody as soon as he learned that Baby Girl was being put up for adoption. Adoptive Couple did not follow the procedural directives in the ICWA to obtain the father’s consent prior to initiating adoption proceedings. The Supreme Court of South Carolina affirmed.

Question
Can a non-custodial parent invoke ICWA to block an adoption voluntarily and lawfully initiated by a non-Indian parent under state law?

Does ICWA define “parent” to include an unwed biological father who has not complied with state law rules to attain legal status as a parent?

More info here:  Baby Girl was 27 months old and had been living with the adoptive couple since birth when South Carolina Supreme Court told them that they were "ideal parents" but they had to turn the the child over to the biological father she had never met. Under state law, the child would stay with the parents, but the federal law "calls for special procedures rooted in the sovereignty of Indian nations and a history of abusive child welfare practices involving Indian children."