the problem might simply be their standards. they have to be purchased. how do you know the supplier got it right?
or it might be that there is a $ reward for “grade inflation”. see Shady Lab Results - #17 by cyclopath
edit: then of course there is
Lies, Damn Lies, and statistics…
and statistically speaking, adding those numbers and getting more than 100% is guaranteed at least some of the time, given the nature of the beast (and the error margins involved).