He's split off from Carrie to cover more ground in the dunj - it's unusually large and labyrinthine, and the portal stone isn't anywhere obvious. The way that the little chittering beetle-like monsters can pour through tiny cracks in the wet, jagged limestone walls, growing at they charge him, is also incredibly annoying and very not helping. He's just finished killing another swarm, and is currently glaring up at the opening to the next room - fifteen feet up and too far from any ledges or handholds for him to safely jump.
Sasuke might be able to manage it anyways, or possibly circle around. He weighs the two options, risk versus time lost circling around.