Pretty sure the company is called Spar 
They’re one of my clients.
Regardless, just because he’s a chemical engineer, doesn’t mean his comments on the topic at hand are accurate. I for one believe it is far more likely that the pumps compensate for density, because the fact that density varies with temperature isn’t exactly a big secret. If it were the case, it wouldn’t be a few guys at NASA knowing about it, and the rest of the world being ignorant. You learn this shit in high school for crying out loud.
Some of the other stuff seems decently credible, about the vapour point of gas, but I don’t actually know what it is, so I can’t vouch for it. It just doesn’t seem as silly as the temperature argument, that’s all.