How is it weak?
Here is a small example. When talking about the divinity of TSBP he mentions that the Torah mentions “like I’ve told you” referencing another source. He makes a huge leap to say “well that proves TSBP is divine.”
While I agree it gives substance to the fact that there is another source given, it in no way shape or form proves that TSBP is divine.
There were plenty of examples in the book that made me think it weak.
Also, we rely on the unbroken mesorah chain to explain away a lot of potential problems. However, if you read Nechemiah, it does talk about a break in Mesorah and a new scroll being found. Yes, mefarshim explain this, but its also easy to say “well, the general population did not have 100% unbroken mesorah.”
I’ve never heard 100% proof of the Torah. I believe in the Torah and believe that it has been passed down from generation to generation and is divine. But that takes a leap of faith. I’m ok with that.