If it's a case is was a runaway trim even at extreme you could still get control of the Aircraft. the problem arises that there are 2 ways to do this which is ease the throttle so there's less friction on the elevation controls which they call the "roller coaster" so that you can manually adjust the trim Or increase airspeed to it's maximum threshold this of course makes it more difficult and normally a 2 man job to adjust the trim.
I think this is reason we see them try and gain control at 8000 and a increase in airspeed. Didn't the flight bank to the left?
Recovery from a Severe Out of Trim
Accelerate or decelerate the airplane to an in-trim airspeed. If a recovery must be initiated from an extreme nose-down out-of-trim requiring a high pull force, an increase in airspeed may relieve enough of the elevator load and control displacement to permit manual trimming. Do not exceed speeed limitation. If a recovery must be initiated from an extreme nose-up out-of-trim requiring a high push force, a decrease in airspeed may relieve enough of the elevator load and control displacement to permit manual trimming. It should be noted that the relationship between airspeed change and trim change do not remain constant. As airspeed is increased, trim change requirements decrease.
In an extreme nose-up out-of-trim condition, requiring almost full forward column, decellerate, extend the flaps and/or reduce thrust to a minimum practical setting consistent with flight conditions until elevator control is established. Do not decrease airspeed below the minimum manouvring speed for the flap configuration. A bank of 30 degrees or more will relieve some force on the control column. This, combined with flap extension and reduced speed, should permit easier manual trimming.