You should not miss the different meanings of "chassis" when you judge hard.
Paul Monaghan is possibly talking about the pure survival cell as the "chassis". Whereas the first measurements were possibly done on the whole "chassis" at the wheelhubs. This would give the answer why they could not find the problem before: At the track the aligning is not done under load, whereas in the factory they have tools to measure the whole car under load.
Maybe even the change of the gearbox helped the rear axle more than the change of the survival cell. This would be even a better reason for not matching rear axle settings as the survival cell ends in front of the engine.
True as it may be, it would not explain RB's quality control and/or operations control at actual racing weekend.
While I may accept that a thorough investigation about a 'chassis distortion' may not have happened during the first few races, I would think that RB has to take measurements (at wheelbase, at the joints, etc.) each time the car is unloaded from the trailer.
I mean, a trailer and a plane is not a stable environment, a lot of vabriations for sure, and RB would have to check this again and again, if VET kept complaining about the behaviour of the car.
To me it sounds more as a convenient excuse for VET's reputation.
On the other hand, he may have to prove now that it was indeed the car and not him.