The way I understood the NTSB briefing was that RTO was not initiated until the airplane had diverged some way from the centerline, perhaps even at the runway edge. The main proof point is that the airplane continued to accelerate from 90 kts, when the first officer noticed leaving the centerline, to a maximum of 119 kts if I remember correctly. If this is correct, the runway main wheel marks are not from braking but from skidding.