Oral arguments on an appeal of a district court judge’s dismissal of a pharmacy chain’s antitrust suit against Allergan became mired in a procedural morass Monday, as judges for the U.S. Court of Appeals for the Third Circuit questioned the defense side’s tactics in moving to have the case tossed.

Hartig Drug Co. asked the appeals court to overturn a ruling by U.S. District Judge Sue L. Robinson of the District of Delaware, in which she dismissed the “product-hopping” case for lack of jurisdiction. A distribution services agreement between Allergan and a direct purchaser of two drugs, she said, barred Hartig from suing for Sherman Antitrust Act violations after Hartig bought the drugs from AmerisourceBergen, its pharmaceutical provider.