When Hurley implored Jenna (a gate attendant) to let him on the plane, she picked up the phone and said, "Hunter, this is Jenna, we've got one more...ta". Hurley was subsequently allowed on the plane.
Given normal procedures, Hunter must be somebody who was watching over the entrance to the plane from the inside out. He was probably a flight attendant, or even the purser. It is possible that he was the same person as the male flight attendant.