In his segment that followed, Dawkins responded this way: "This leaves open the question of where did the creator come from?" Since the creator is this "great big complicated thing," what good does it do to invoke one complex thing to explain another? "If you postulate a designer you haven't explained anything." Basically what Dawkins is saying is that there is no point in using complex explanation A to account for complex phenomenon B if you cannot account for A.
This is a fallacy. We can see this by applying the logic to evolution itself. The logic of evolution is a "great big complicated thing" with all its elements of replication, natural selection, mutations, genetic drift, and so on. Yet it is invoked to explain another complicated thing: the exquisite fit between living creatures and their surroundings.
How reasonable would it be to argue: "We are invoking one complicated thing, namely evolution, to explain another, namely living things. Yet this leaves open the question of where evolution came from. We have no idea how and why evolution originally started. Since we cannot account for evolution, our explanation is useless. Simply to postulate evolution is to explain nothing." This is precisely Dawkins's argument regarding God, and here we can see how it boomerangs on evolution!
But consider the argument itself more closely. Is it really true that Complex Explanation A for Complex Phenomenon B only works if we can give a full account of A? Actually it is not true. Gravity may account for why objects fall at a certain pace, but this does not require that we give an account for where gravity comes from or why it exists in the first place. If we find various signs of intelligent life on another planet we can conclude that there are aliens on that planet without having any idea of who created them or where they came from. In summary, the best explanation for something does not require that we also provide an explanation for the explanation.
The problem I think for Dawkins is that his trademark snorts and sneers only work against weak opponents who do not do much more than hurl Bible verses at their opponents. When he is confronted with history, philosophy, and logic, Dawkins seems to have very little to say. And perhaps this explains his peculiar insistence that I be given no chance whatever to respond to his statements on the Riz Khan show.