The reason? No one thought they had jurisdiction to decide his application! This is what happens when your system is made up of so many parts that don't always work together. It's kind of like driving a car pressing the gas and the brake at the same time.
In this case, it has to do with certain aliens in removal proceedings who have ported employers under INA 204(j). This section of law was passed as part of the American Competitiveness in the 21st Century Act (often abbreviated "AC21") and helps remedy the interminably long process of getting a green card based on employment by a US employer. Since these cases took so long, aliens took a big risk: there was no guarantee the employer would still be around by the time the government was able to decide his green card application. So 204(j) allows aliens who have a green card application pending for more than 180 days to switch employers, so long as the new position is "the same or substantially similar occupation" as the one for which he was originally petitioned for.
The problem arose in the case of an alien in removal proceedings. An employer petition is filed with USCIS, which is the only agency that can decide that petition. Once an alien is in removal proceedings, the immigration judge is the only one who can decide the alien's green card application, and USCIS has no power to do so.
Ordinarily then, an immigration judge will wait for the petition to be approved or denied by USCIS, and then decide the green card application accordingly. But when an alien changes employers, then someone has to judge whether the new position is the "same or substantially similar" occupation as the original. Who decides?
Well, USCIS refused to do so. In 2005 the Board of Immigration Appeals decided Matter of Perez Vargas, 23 I&N Dec. 829 (BIA 2005), and said that immigration judges couldn't either. So employment sponsored aliens in removal proceedings were at an impasse. No one would adjudicate their green card applications!
Happily, the Board reversed itself. After Perez Vargas was shot down by the Fourth, Fifth and Sixth Circuits, on January 21, 2010 the Board decided Matter of Marcal Neto, 23 I&N Dec. 169 (BIA 2010), concluding that immigration judges do in fact have the jurisdiction over 204(j) employer ports.
Great news for an undoubtedly large class of aliens whose files likely landed in the office of a Detention & Removal officer. If you are (or were) in removal proceedings and your case was denied or administratively closed because the Court concluded it couldn't decide your application because you switched employers, contact an attorney now.