He gives Ed Mercer command of the Orville despite his notoriously irresponsible behavior. It is later revealed the reason Halsey made such a decision was because Kelly Grayson issued a plea to the Planetary Union to do so. Without such a request, Ed would not have received command of the Orville.
Ed Mercer confronts Halsey after finding out that the Admiral only granted him Command of The Orville due to Kelly Grayson's pleases to do so. Halsey insists that the reason he was originally promoted is irrelevant, as Mercer has proven that he has the conviction and skills to successfully lead a Union Ship well on his own.