Jack testifies for Kate

Jack shows up in another flash forward to testify at Kate's trial. During his testimony, we learn a little about the story that the Oceanic 6 are telling the public including that 8 people survived the crash, the marshal died in the crash and that Kate saved the day by giving first aid and finding water and food. If 8 people survived, why is there only the Oceanic 6? Interesting, no?