Are you serious? Orochimaru stopped him and gave Naruto and co. a reason to live. Sasuke was well within the mindset to murder them all, and it was well within his power to.Sasuke ran away! & another honorable mention is naruto saving sasuke from p-1 gaara's rampage!
As for Gaara, A>B>C scenarios don't work in Naruto. Besides the fact that Sasuke had already battled Gaara previously and spent valuable amounts of chakra.