I am pretty sure Phill understands how bitcoin works, however, there is no right/wrong way of valuing things, you look at it from BTC perspective, he looks at it from fiat perspective.

In fact, I also prefer looking at everything mining related from a BTC standard, and when I do so, I realise that mining whole together is somewhat a terrible business, in the vast majority of cases, the BTC you spend on gears and infrastructure is probably never going to be ROIed, you may ROI on your fiat capital and that is a different thing.

With that said, in the U.S and other places ( probably no other place lol) where the tax law is so complicated, it becomes a different matter than just fiat vs btc.