The question should be, is the baby his or is it not? If he provided the male part of the DNA then he should be responsible.
It shouldn’t matter if a doctor was involved or not
“It shouldn’t matter if a doctor was involved or not”
That was pretty much my point. I’m not so sure about your first point, even though you have the courts on your side. Two women, purporting to be a couple, asked the guy to donate the missing half of the chromosomes necessary to make a baby. If they’d gone to a sperm bank, and had a doctor perform the rituals, then settled law says that the “couple” would be responsible for all child-rearing expenses. If it shouldn’t matter if a doctor was involved or not (and I don’t think it should) then either all sperm donors are on the hook — or none should be. The ruling on this case is inconsistent.