Do you know what that 8% means? His OBP in the situation is ~.300, so his career OBP of .392 is only 1.2% outside the margin of "expected" error. Pulling 2.4% of the data from 5000+ data points, it's very possible you get something like his bases-loaded results. Furthermore, he's demonstrated success similar to his career production in many other "run scoring" situations. You cherry picked.
And, as far as RC vs. RC/27 goes. I didn't suggest one was a better analytical tool for determining JD Drew's worth. It was better for answering the specific question that you attempted to answer and botched. FTR, since you suggest it doesn't change things much, JD Drew was 3rd among qualified RF(source espn.com). Again, I realize that RC captures the playing time that has worth, but don't make s*** up.