Those bums shouldn't take foreign law into any decision they make because it is not law in this country.
Actually, since ante-bellum America, the courts here have looked to foreign law, particularly British law, because our system is founded upon English legal principles of equity and common law. The founders of our country who were lawyers were schooled and practiced the principles of English law and equity. And Blackstone's Commentaries are repeatedly cited in legal opinions of this country. It is also notable that the friezes on two walls of the Supreme Court chamber are lined with great lawgivers who have contributed to the development of our laws-- and there is only one American on that frieze-- John Marshall.
So, it is not unusual. But, I think the danger lies when Constitutional principles might be undermined by foreign influence. While foreign law might be of interest comparatively, it is not precedent.
BTW, it is also commonplace for courts in maritime cases to look at foreign law.