Think about it quantitatively. MDMA has always been tops in the rankings (not just this one, but DARCs and others), implying it's been sold to at least tens of thousands of customers. If the worst MDMA would rank 1 and normal MDMA 5 and half the MDMA sold is bad (to maximize the possible impact on the rating), then you'd have to have thousands of people croaking after taking the bad MDMA in order to produce an average of 4.9 (to pull down the average by .1 using ratings of 1). In contrast, I've seen media reports of maybe 2 deaths clearly linked to drugs bought off the black-markets (psychedelics which were RCs and led to fatal accidents).