cofty, he asked all three of those questions, since none of our answers said "God did it". I think he is also saying that the alleged naturalistic processes which created the first cell must be thought of as having begun as far back as the beginning of the universe (if we say the universe had a beginning), and even further back to what caused the big bang, and thus to what existed prior to the universe. His line of questioning is ultimately endless.
He might perceive our science based answers as like saying "it's turtles all the way down", and thus he wants us to trace it all the way down to the ultimate origin. He knows that no one knows the scientific answer to all the way to the very beginning (even if someone says it fluctuations of quantum foam, and/or of virtual particles, in the vacuum). He thus feels he is at an advantage of simply saying God has always existed and that God began the existence of everything which is not God.
Physicist Lawrence M. Krauss in his book called A Universe From Nothing (or in a comment about it) raised the issue of if the origin of the universe amounts to the metaphor of "it's turtles all the way down", and he said he does not think so, but he does not say what the ultimate origin was, for he doesn't know. But https://en.wikipedia.org/wiki/Lawrence_Krauss says the following about Krauss' view.
'In his book A Universe from Nothing: Why There is Something Rather than Nothing (2012), Krauss discusses the premise that something cannot come from nothing, which has often been used as an argument for the existence of a prime mover. He has since argued in a debate with John Ellis and Don Cupitt that the laws of physics allow for the Universe to be created from nothing. "What would be the characteristics of a universe that was created from nothing, just with the laws of physics and without any supernatural shenanigans? The characteristics of the universe would be precisely those of the ones we live in." In an interview with The Atlantic, however, he states that he has never claimed that "questions about origins are over". According to Krauss, "I don't ever claim to resolve that infinite regress of why-why-why-why-why; as far as I'm concerned it's turtles all the way down". '