But, they are just that - facts. The fact of the matter before us is that it takes 27.7 inches of water column to create 1 PSI at the bottom of the column. 55.4 inches of water column creates 2 PSI, and so on. It doesn't matter if the water column is 500 yards long or 3/4 inch pipe or 6 inch pipe. As long as the vertical difference of the water column contained within it is 27.7 inches the net result will be 1 PSI at the bottom. This is a fact that is true even in the world you live in and your buddy's world, too. Of course, if he lives on a planet other than the one I inhabit it might be different due to gravitational strength differences. If he does, let me know and I'll calculate that for you.
Big pipe will flow more volume than small pipe. As c. chuck pointed out, your friend saved some on the cost of pipe by making it smaller and smaller. He did so at the cost of flow potential. There's always the possibility your friend doesn't need as much flow rate as the big pipe will allow but, at the same time, he won't get any more flow rate than the spring will allow into the pipe in the first place. In fact, he'll get less due to friction losses in the run of pipe he installed. By doing what he did, he still gets flow loss due to internal pipe friction but he doesn't have as much loss as he would have if he had ran the smaller size pipe all the way to the stream. In that sense, I guess he did OK. He didn't change the static pressure in the pipe, though.
True, I didn't want Trump to win. I wanted Ted Cruz to win. But, Trump won anyway and even though I don't always agree with him I still think he's a much better choice than anybody else in the running coming into the election this year.