As already discussed, the runaway trim procedure got them to a positive rate climb.
Then they did A) re-enabled electric trim (and MCAS) B) while still low, C) touched the trim button for a second, and didn't adjust anywhere close to proper trim, and D) left electric trim/MCAS on.
Not to mention, from your source, the FCTM says:
> Excessive airloads on the stabilizer may require effort by both pilots to correct the mis-trim. In extreme cases it may be necessary to aerodynamically relieve the airloads to allow manual trimming. Accelerate or decelerate towards the in-trim speed while attempting to trim manually.
Then they did A) re-enabled electric trim (and MCAS) B) while still low, C) touched the trim button for a second, and didn't adjust anywhere close to proper trim, and D) left electric trim/MCAS on.
Not to mention, from your source, the FCTM says:
> Excessive airloads on the stabilizer may require effort by both pilots to correct the mis-trim. In extreme cases it may be necessary to aerodynamically relieve the airloads to allow manual trimming. Accelerate or decelerate towards the in-trim speed while attempting to trim manually.