Ryan -- the little 'flair' you added at the top of your stitch line gives a nice line to the sheath and compliments the drop line of the knife handle. It looks like the added width of the welt in that area needs the double stitch line to secure it, so the double stitch is not only attractive but also functional. I say good work, keep it up.
I would add that I agree partially with the advice you got from your sheathmaker: you could get better knife retention by not having the top of the sheath cut down below the handle. But if you are satisfied with the retention, then the design becomes a matter of personal choice.
Let's see some more of your work
Mike