The indictment’s reference to City Hall was “curious,” said Roger I. Abrams, a labor law specialist and professor at Northeastern Law School. The phone calls did not appear to cross a line, Abrams said, but the sentence mentioning the city official was not included by mistake.

“It’s not superfluous. Normally, those indictments do not contain as we lawyers like to say, ‘mere surpluses,’ ” Abrams said.