First thing to keep in mind is these trucks are smaller than your f150, so they need less side wall to look proportionate.
You are aware that the series of the tire is an aspect ratio in relation to the width, right? On a 50 series tire as wide as say a 275 or 285 the side wall will be about 5.6 inches, where as on a tire as narrow as a 195 or 205 the side wall will be bout 3 inches. So just because a tire is a 50 series and people's opinions of what is low profile is, doesn't necessarily make it a low profile tire. The stock 225/75r15's that came on my truck had about a 6.6" side wall, not considered a low pro. The side wall on a 285/50 would be just about 1" shorter than the stock tire side wall, just on a bigger wheel. The 265/50 would have about a 5.25" side wall, just 1.5" shorter side wall than my stocks. The 33x12.50x20's I'm running now have about a 6.5" side wall, now is the side wall on my 33's shorter than the side wall on a 33x12.50x15? Yes, but I still wouldn't consider it low pro. Now with all of that being said, and with his truck being newer than '09 his truck came with 16's and I don't know his stock tire size, it may have .5" smaller side wall than mine from the factory.