Maybe it was his intention or by accident, but his method makes since in my world, basically the same way wrapping butts and brisket works.
What happens in this method is you are actually braising the meat in the liquid or its own juices. The combination of the liquids are really a personal choice. Depending on what liquids you use will in my eyes determine weather the meat needs to be down to get the effect of the flavors. If you use a broth or water only based liquid it does not matter, the steam theory will work. However if you have a fat based liquid (margarine, butter, bacon fat, etc...) for flavor your meat needs to be down to get all of the flavors, fat does not steam and you will not get all ofnthe flavors in all of the meat. In my experience with playing with this method going meat side up is more forgiving then meat side down, but meat side down with what I use gets more flavor since the meat is in the liquid. Because the meat is in the liquid it will cook faster and can over cook very quickly.
Yes, he has a set recipe he uses, but you can adjust as you see fit for you and your guests taste. If it is too sweet, back off the sugar or honey. Too hot, dont add the tiger sauce. I glaze mine with a little bbq sauce mixed with some of the drippings and lightly dust with a finishing seasoning that has no sugar.
This is some of my last ribs I did this method. 3 - 1 - .5 @ 250-275 meat side down