India 42, The guts of it is that the missing spacer enabled the wheels to migrate from designed positions and led to a strong left drag on the left truck by their twisting a bit left. This cost acceleration due to wheels not tracking along the longitudinal axis of the a/c and hence scrubbing a bit sideways. There was a drag induced by the necessity to steer right as well. This all cost energy and reduced performance of an a/c already over limits.
If the a/c had tracked the runway c/l there would likely have been no incident notwithstanding the huge performance discrepancies.