The image of the original slide only mentions 5AZA on the positive samples. If 5AZA was only added to those samples (as the labelling on the IACFS/ME slide would also seem to indicate) then that's a very important thing, that needed to be mentioned (as would any other difference between how different samples were treated/prepared). Also, the IACFS/ME slide claims that two of the negative samples were from the same patients as the positive results, but without 5AZA. While the science paper shows them as all coming from different people. I'm not claiming that I know what all this means, or what led to these different labels being used, I'm not sure that anyone does yet, but these differences are potentially problematic.