A couple things I drew from the report:
At no time did they reduce power. The airplane would be MUCH more sensitive to pitch commands as it neared VMO, hence much less controllable in the out-of-trim condition. IF the autothrottle was still engaged, they did NOT follow the non-normal procedure (Step 3) for Runaway trim.
At no time did they get the pitch trim back near an in-trim position. Granted, less nose-up trim would be needed at the high speed, but they continued to use aft column force in lieu of more trim.
It is unclear when/if they returned the Stab Trim Cutout switches to the Normal position at the 5:43:11 point. We may see that later IF there is a FDR trace for those switch positions. However, IF one or both of the Cutout switches were returned to normal, why was there NO yoke trim input after that? If I were to try that last-ditch move of re-engaging the stab trim, I would FIRST hold the yoke trim switches to the nose-up position...