How often do law departments encounter HR resistance when they want to use a search firm?

Consider a point made by Mike Evers, a recruiter for attorneys, in InsideCounsel, June 2006 at 92. When a general counsel wants to fill “staff attorney” role, which Evers describes as a junior level lawyer, the title may turn off good candidates. “Worse yet, your HR department may fight your desire to use a search firm to fill a staff attorney opening, leaving you at the mercy of Internet job sites if you refuse to wage a turf war.”

Put aside his assumption that only one source remains if a search firm is scotched (See my post of March 26, 2007 on sources of hires.). If the budget of the law department can absorb the fees of an executive search firm, why should HR have any say in whether the department can use such a firm? If the fees hit the budget of HR, then they properly should have some say.