After looking at the OpenADSB Exchange and running 0A9-SARDI-CCC-KISP-0A9 I changed my mind: KISP-0A9 while indeed very close to the airplane’s final track they aren’t the same. CCC-KISP is only two degrees difference than KISP-0A9, and the airplane’s track didn’t change after crossing KISP and an extension of the projected track would have passed south of 0A9.
So, the airplane doesn’t appear to be holding a heading on the final leg but simply an extension of the CCC-KISP course.