@runiggyrun pretty much covered it. When they say "challenges the accuracy of the evidence" it often looks like the author is attacking the premise. In the example above, Mary attacks John's statistics (i.e. 90% is NOT accurate).
Internships are pretty much irrelevant. LSAT & GPA combined weight ~90% in terms of your admissions chances outside of Y/S & assuming you're not a URM. The only softs that significantly help are Rhodes, Olympian, etc.
... 1% of students get >90 and an additional 10% get ... 80-90% and in another country 30 ... % get >90% and another 20% get 80 ... -90%, the same grade of 80% ...