I agree, jwalsh07! It just seems that, in this case, they would've been separated, anyway. Here's information about the adoption agency from the other article:
"The twins found that he was willingly aided by the Louise Wise adoption agency that handled both their adoptions. Viola Bernard, a child psychologist and consultant to the agency, had firmly believed that twins should be raised separately to improve their psychological development, and that dressing and treating them the same retarded their minds. Separating twins at birth was ended in the state of New York in 1980, a year after the study ended."
That's why I think the adoption agency is to blame in this story. For the record, I don't think siblings should be separated, whether they're twins or not. I'm glad that old policy was ended.
No one's much interested in facts when they get in the way of their righteous indignation.