"I know you have a great deal of respect for this guy, but keep in mind that he is still human and has a strong incentive to prove his own correct-ness. He already knows the answer he wants to come to, so once he finds a way to get to that answer, regardless of how reliant that way is on semantics, he will stop searching, so he never goes on to see the flaws in his reasoning."
This is not the case with Matt Dillahunty. Yes, he's only human and he is capable of error, as am I, but my respect for him comes from knowing his sincerity in seeking and speaking truth in logic. The atheist experience is a great show that covers many topics and arguments regarding atheism and freedom from religion.
I'm sorry it took me so long to get back to you. I found the belief video that he referenced in the video that I sent you. it's an hour long and it's great, but it's really difficult for me to quickly learn how to argue his points. I've watched it multiple times before responding so that I could both understand and repeat what was said in my own words.
Chances are, that I will misrepresent what he's saying because I'm still learning about these arguments, but unlike many religious followers, I will follow through with challenging my position and I will be openly willing to adjust my view to fit objective reality.
"Do you see the problem with this? If you don't believe the claim that there is a god nor the claim that there is no God, what position are you left with? Uncertainty, also known in this case as agnosticism."
Actually, in the belief video which I will attach to this post, he points out the difference between saying that an agnostic claim is that you don't know something verses the claim that you can't know. Matt accepts that he is an agnostic based on the first definition, but not by the second. If you claim that we can't know if there is a deity, then you have made a claim which you still need to demonstrate as true. You still need to demonstrate that knowledge of a deity's existence is unknowable and why it is unknowable.
Another point being made is that there are different questions being asked when we consider atheism and agnosticism. Atheism is a belief in response to a claim that a God exists, whereas agnosticism is a stance regarding knowledge of a truth claim. It's because of this difference that it's reasonable for a person to identify as an Atheist Agnostic.
"...with the weak justification that you can't have a single belief about multiple claims, which is false) and then asserting that the default position is always negative."
I'm pretty sure that he's not saying that. The justification of atheism being the default position is related to the reasons we say that a defendant is guilty vs not guilty rather than innocent vs not innocent. It's more practical and useful in determining truths even of claims which if true are indistinguishable from if they are not true. Either way, we should not be strongly acting upon what we do not know to a high degree of certainty.
That's in essence what makes Atheism the default position. Since a Deist God has no impact on our lives and is indistinguishable from the non existence of such a god, it's more rational to live by the idea that such a thing doesn't exist, otherwise you would be showing equal support to all metaphysical claims.
Any action that you take towards acting upon such beliefs is wasted effort, even to an extent of just thinking about the possibility of them being true/real because there's no way of telling which of those beliefs holding zero evidence are simply not true/real and the many different claims that would fall into the realm of potential but not true/real are infinite. It's also not possible for all potential realities to be true, because an infinite set of those potential realities would contradict one another.
The atheist position is therefore the default position because it's the more practical position to take when concerning matters of belief which match with reality. Why is it that you would even concern yourself with the possibility of a Deist God any more than you would concern yourself with the possibility that all matter in the universe is made out of invisible marshmallows? I would posit the likely reason being something to do with you wanting there to be a God or some sort of thing out there that explains your existence or else falls in line with the metaphysical beliefs that you were brought up to concern yourself with and that all of the reasons for why you got to that point can be explained with objective evidence.