It's clear you really want to believe this, but it isn't true.Posting that Sims & Stephens are "likely bound by NDAs" is pure speculation that doesn't give their comments about ttrpg sales numbers any real value. They're essentially saying "Trust me, bro"
Meanwhile, ICv2 is a trusted source of sales data for several industries, not just ttrpgs. D&D being outsold by Pathfinder would be a big deal, big enough to impact D&D's market value. If ICv2's numbers were off, why wouldn't Hasbro issue an official statement pointing out the errors?
Your argument doesn't make sense. Not good business sense, anyway.
I seem to remember that Amazon had a really good deal on the core 4e books on release, and that's where I think everyone in my group got their books. Later I bought Martial Power 1 as a pdf and some in my group were subscribers to whatever the digital thing was called. We hardly bought anything from an LGS.