However, not a single person on this planet kept their blood glucose dead still after eating any type of carbs. Ergo, it's not that some carbs don't do anything, it's that the effect varies but is never zero. Accordingly, there's no a priori validity to any claim that anybody can remain lean while eating carbs of any kind. Rather, there's absolutely no validity to any claim that carbs can somehow cause the complete opposite effect from expected.

Note how Robb describes it:

The word tolerate is not synonymous with the word immune. To tolerate means to put up with [its effect, the trouble, the pain, etc]. It does not mean to get through it unaffected. What Robb actually meant was:

"...by finding out which types of carbs we can put up with."

Well, I put up with a whole lotta carbs for most of my life, then I realized what all those carbs did to me bit by bit over a few decades and decided I'd had enough of that crap. Oh, I can tolerate a ton of carbs even today, I just choose not to.