Resolution counting is a manual process and finding range of dynamic resolution is even harder in that you have to take a screenshot from what you think is a high load area and THEN count the frames manually. When you add in things like TAA and reconstruction it means your pool of available screenshots that give you a non reconstructed image becomes even smaller as it has to be a frame taken right before the reconstruction comes into effect. A 60FPS game will have some 216000 frames captured in an hour's worth of footage. Trying to find that one screenshot with the lowest possible resolution AND without reconstruction is not going to be easy.
Then you have to factor in that dynamic res ends up being a case by case basis. The game may drop the resolution for me but not for you, in the same area as it's dependent on so many variables from your personal playstyle, exact location on a map and what you are looking at, placement of enemies, the actual action happening on screen.
In short, it's super hard as it's done manually..there's no tool that goes " find me the lowest possible resolution from this capture" and it's easily possible to miss some things especially given the timeframe they are given to make videos.
If only more people understood this.
Having said that, I wish these conversations didn't result in people pitting tech analysis channels against each other. It's a good thing for multiple outlets like Digital Foundry, VG Tech, GameXplain, etc. to co-exist and be able to provide different data points in a similar way to researchers conducting their own studies but still based on the same objective. In other words, objective measurement is valuable, but aggregated objective data even moreso, so it makes zero sense for people to try to devalue one channel just to praise another; we should be evaluating all the data as a whole and appreciating everyone who contributes to synthesizing that data.