I'm now the father of twin girls (fraternal) and they are basically two completely different human beings who happened to share the same womb and birthday. They are NOTHING alike.
I also have 2 other siblings, and though I communicate the least with my twin these days - I still feel and share a bond with him that I'll never have with my other siblings and I can't quite explain it.
All that said I can't wrap my head around this idea that twins "think alike because they're twins." I think the simple answer to this case is that both of those women are smart and studied hard. And if you're really worried about it - put them in different classrooms and make them re-take the test. Sure would have saved a bunch of time and legal fee's!