Simply not true IMO, even if the non flying pilot adds nose down input without pushing red button the actual command output is a blend of the two side stick inputs and the attitude will be reduced, secondly, most left seaters are well aware of problems caused by DUAL INPUTS, thumbs at the ready, especially on final
1- Whatever action will have the PM on his sidestick, he's already one step behind, as his action will be based only on the developping airplane attitude and not knowing what kind of input was requested on the other side.
2- And what happen if at the same time the PF realizes his mistake and decides also to push forward his sidestick ... !?
3- "a blend of 2 sidestick inputs" ... WHAT A MESS !
4- RED BUTTON theory and practice are two very different things.
How many times did you hit that red button in the flare ?
How many times did you hit that red button in the rotation ?
Did you ever think afterwards:
Maybe I should have …
But I didn't get the proper information ...
And I didn't get time ...
For those of us trained on the Airbus, we realize that Direct Law is not required or desired, the beauty of the airplane is that I can yank the stick in whatever direction I want to get the desired effect, regardless of configuration without causing a stall or hurting the airframe, does it work that way on the 744?
It is actually a great feature.
But once again, how many times did you use it ?
What about airmanship (basic training, skills, rules) ?
I will not argue on that point:
It is a great feature,
but still, does not replace a pair of good control columns when most needed.
And I believe all big airplane manufactures understood that ...
probably thanks to that early Airbus move.