[Shandrax]

I never know if I should take Caro verbally or look for a deeper meaning behind his words.

Sure, if two players play a mathematical game to perfection they can't beat each other. Another factor has to decide and that's either the cards on a given day or psychology over the long run. If you see it like that, then he could be right. On the other side, every deviation from perfect math should show a loss over time, so he could be wrong.
Maybe he was simply talking about no-limit, where you can set up an opponent by making countless bad plays over the night to trick him to lose all his money in one hand. Sure it takes a fool to fall for that, but that's what psychology is all about - using intellectual dominance to manipulate someone.

If his comment can be interpreted as an insult or a personal attack on David and Mason, I don't know. Actually I wouldn't take it that serious. Caro likes to display himself as some sort of mad genius. Just book stuff like that under madness and you should be fine.

Furthermore I doubt that statements like this will hurt 2+2 sales. Caro is too much of a freak to appeal to the more analytical type of reader and those are the folks who buy 2+2 books after all. Just watch the Caro poker video and you can see what his target audience looks like. It's the type of guy who finds Hellmuth too complicated to read.