Well, the young kid who helped him (one of the four dome kids)bring Julia to the hospital AND the nurse who saw how Barbee helped her might help too. BUT, Big Jim KNOWS Julia is still alive. Will he try to kill her since he doesn't know her condition and/or if she can testify on Barbee's behalf.
TIS
Well, technically, nobody saw who shot Julia, except for Julia. So that's not going to help. This is a guess, but I think Jim wanting to kill Julia would be ultimately the reason those four would do what they do. But this is a guess obviously. Knowing Jim, he might do a lot of other awful things that warrants what's coming to him.
"Fire cannot kill a dragon." -Daenerys Targaryen, Game of Thrones
