No, I mean the lighter arrow will actually have more KE than the heavier arrow within a narrow weight range. I have found this to be around 4.5 to 5 gr/lb. If you get much heavier than this the heavy arrow wins,like you would expect, and if you go lower (which I don't do but on rare occasions for testing), the heavier arrow wins again......it's just in a narrow weight range that some bows experience a dramatic enough speed increase that a lower weight arrow can generate more KE than a heavier.

It's rare, and pretty cool. That's the only reason I mentioned it. I probably would not have mentioned it or discounted it as due to some error on my part, but when Mr. Mullany observed the same thing, I felt vindicated.