There's absolutely zero reason for any Stars fans to panic. I'd argue that the points scored is quite encouraging. Had Kvech scored 8-9 (expected) at No5 the result could easily have been reversed.
Regardless of how they got the points, 4 from Castagna & 3 from Rushen is fine.
Move the top 5 riding order to:-
1, Fricke 2, Castagna 3, Kvech 4, Harris, 5, Cook,
it will be far more solid