This must have been the preferential treatment Michael Goldfarb was referring to. From a 1978 WaPo article (referenced in today's Washington Times):

A large Washington law firm-Shaw, Pittman, Potts & Trowbridge-has been forced to apologize to a Yale Law School senior after a student-faculty tribunal found one of its partners had asked her "discriminatory" questions focusing on her being a Puerto Rican.

The tribunal found the questions, asked during a recruiting dinner, violated Yale rules against discrimination. The questions, according to the tribunal, included: 'Do law firms do a disservice by hiring minority students who the firms know do not have the necessary credentials and will then fire in three to four years? Would I have been admitted to the law school if I were not a Puerto Rican? Was I culturally deprived?"

In a letter of apology this week, Shaw Pittman's senior parnter, Ramsay D. Potts, called the questions by Martin Krall "insensitive and regrettable", and acknowledged "they may have had a chilling effect on the firm's recruitment of minorities and other students.

But Potts said that neither the firm nor Krall had "discriminatory motives or intent."

Krall asked the questions of Sonia Sotomayor de Noonan, a resident of the Bronx, N.Y., who had graduated from Princetown before going to Yale Law, during a dinner in New Haven Oct. 2 with several other Yale students.

Then again, maybe Goldfarb will argue that Shaw Pittman's apology itself is evidence of preferential treatment.

Update: I should have known better. Goldfarb actually does believe the Shaw Pittman incident represents preferential treatment:

Not only was Sotomayor offered the job, which she turned down in protest, but she received an apology from the law firm for questions she complained were inappropriate -- a complaint that led to the formation of "student-faculty tribunal."

New Republic

Jason Zengerle