Dr. Craig is a liar.

[Esquilax]

First, regarding your favorite part, WLC, says "...all of the models that Dr. Carroll has mentioned have been shown to be either untenable or not to avert the beginning of the universe.[24] Alex Vilenkin says flatly, “there are no models at this time that give a satisfactory model for a universe without a beginning.”[25] footnoted as: https://www.youtube.com/watch?v=NXCQelhKJ7A

Which is an argument from ignorance, for one, and also irrelevant to the point I was making, which is that the Borde-Guth-Vilenkin theorem does not support the idea that the universe had a beginning. That's not even a conclusion that it countenances. Have you read it? I have: the "chief conclusion" of the paper is that beyond a certain point in time, our ability to describe spacetime in a classical sense breaks down, which is something Carroll points out to correct WLC. The BGV theorem concludes that what's required is a new set of physical laws and lexicon to describe what goes on beyond that point, which is something we haven't developed yet, let alone even developed the technology by which we could detect the observations we'd need to begin on that score.

The conclusions of the paper match the current scientific consensus: not that the universe has a beginning, but that we don't know, and are not currently equipped to know. What we can conclude is that, after a specific point on the timeline, we are no longer safe in applying models reflective of the universe we can observe, to the universe that was. Craig is, quite simply, misrepresenting the theorem by asserting that it even suggests that the universe definitively had a beginning, and you can do what Craig has done, and say that all of Carrol's models don't work, but to assert that because Carrol cannot provide an alternative Craig's bald assertion that isn't reflected in the paper must be true is an argument from ignorance, which Craig as a philosopher should definitely have been able to spot, and probably would have, had it not confirmed what he wants to be true.

Vilenkin, by the way, is also speaking about classical spacetime models- the only ones we have enough data to create workable theorems around- when he talks about the beginning of the universe, which is a subtle distinction but an important one that Craig is overly, suspiciously willing to gloss over when he talks about it: Vilenkin talks about our current, expansionary universe, and Craig wrongly interprets this to mean reality as a whole, which it doesn't. Universal expansion began at the Big Bang, a point in time beyond which our understanding breaks down, but the beginning of the expansion is not the same thing as the beginning of the universe as a whole, and Vilenkin, as demonstrated in the conclusions of his work with Borde and Guth, is not willing to speculate beyond that point. So... no, you're wrong on every point, here.

and later on... "Dr. Carroll does hold out hope that quantum cosmology might serve to restore the past eternality of the universe; but I would say that not only is there no evidence for such a hope, but I would agree with Vilenkin that if there is a quantum gravity regime prior to the Planck Time, then that just is the beginning of the universe. 

So when we come to your favorite part with Alan Guth, what does he say: “I don’t know whether the universe had a beginning. I suspect the universe didn’t have a beginning. It’s very likely eternal but nobody knows.” what is he really saying. That his theorum avoids a beginning? (no) That he considers the quantum gravity regime prior to Planck time to be eternal? (perhaps) That he realizes that the question cannot be answered by science? (possibly). 

Your last potential answer- with the addition of a "yet" in there somewhere- is the primary conclusion of the theorem. You don't need to speculate at all, on this point: just look at the writing itself. If the theorem is a good citation then its conclusion does not match Craig's assertions, and he is wrong. If it isn't, then why is Craig using it at all?

"Dr. Carroll says you can have quantum descriptions of the universe that are eternal, and that is certainly true, but the question is: why would the universe transition to classical spacetime just 13 billion years ago? It could not have existed from infinity past in an unstable quantum state and then just 13 billion years ago transition to classical spacetime. It would have done it from eternity past, if at all."

What a completely nonsensical statement: if the universe expanded into linear spacetime then, even taking Craig's rather bizarre notions about infinities seriously, from that point on you would have a measurable chronological progression, in which 13 billions years have currently passed. From that point out it would have to have been some positive number, it's impossible that you could be existing in a universe that had developed linear time without that linear time having come into existence X number of years ago. What is even the problem here?

But let's take it back to the beginning: you challenged us to present a single example of Craig not understanding the science in the debate. Craig cites the Borde-Guth-Vilenkin theorem as proof that the universe has a beginning. I have a copy of that paper right here: so what does it have to say about the boundary point that Craig asserts is the beginning of the universe?

What can lie beyond this boundary?

Why would you even need to ask that, if your paper concluded that this boundary is the beginning of the universe? If it's the creation event, nothing lies beyond it.

Whatever the possibilities for the boundary, it is clear
that unless the averaged expansion condition can somehow
be avoided for all past-directed geodesics, inflation
alone is not sufficient to provide a complete description of
the Universe, and some new physics is necessary in order
to determine the correct conditions at the boundary [20].
This is the chief result of our paper.

The "chief result" of the paper is not that the universe had a beginning, but that beyond the beginning of the expansion boundary, new physics are required to give accurate descriptions. In fact, the conclusion actually brings up a potentially eternal model of the universe, a recycling model, that fits right into their physics, but that requires additional analyses. So not only do the actual conclusions specifically avoid giving an answer on the beginning of the universe, not only are they ill suited to actually do so anyway, but they bring up an alternative that matches an eternal universe just fine.

Now that you know this, now that you've had it directly quoted to you from the paper itself- and there are pdfs of it online if you cared to read them- do you agree that Craig's assertion that the paper demonstrates the universe had a beginning is incorrect? Was Craig wrong on the science here, since you now know what the contents of the science actually are?