No you don't. You have no evidence of that,
Yes, I do have evidence, and I told you what it is:
The very existence of stage 1 is the evidence! The fact that during stage 1, the entire north wall fell at increasing acceleration. A structural assembly that startet out standing still on the ground falls only when structural members below buckle.
So the existence of a falling wall is the evidence that columns below buckled. Had they not buckled, nothing would have moved.
The fact that they fell at less than g during stage 1 is prove that all columns were not severed simultaneously by explosives.
So stage 1 is the evidence that all columns on the north wall buckled gradually, until, at the beginning of stage 2, they all had buckled completely.
and for the most part, what you said doesn't even make sense.
For the most part, you, personally, just dont grasp the sense.
Once collapse is initiated, columns meet the upward force applied by the ground (and growing debris pile) below them.
Only if the coluns are unbuckled all the way up from the ground.
The fact that the entire wall already fell during stage 1 proves 100% that the columns were not unbuckled.
There is no evidence that all of these columns had already buckled before encountering this force.
Explain how all og the north wall could move downwards during stage 1 if not all of the columns below were in the process of buckling!
If you have it, show it. You'd think NIST would have demonstrated such evidence when they admitted free fall in the first place. They didn't.
I have it: Stage 1. That's when the north wall already fell, but not yet at g, which means that some resistance was left. During stage 1, acceleration increased, which means that gradually, resistance decreased. This is equivalent to columns (all of them, because all of the north wall fell as a unit) gradually buckling instead of being instantaneously severed by explosives or the like.