The universe does not necessarily behave in accordance with the human concept of cause and effect.
Especially since the human concept of cause and effect is just that--a concept, useful for everyday human thinking, but a concept that may have no basis in reality.
All we have are concepts. We measure their usefulness by their correlation with observed experience. We build axioms and logical arguments from this.
Hawkins uses logical arguments - albeit with a very uneducated view of theology. So it is entirely proper to engage his arguments logically as well. And the prime mover/first cause argument is still a good one.
Where did I say I was referring to the human concept of cause and effect? I am speaking about the laws of motion. Does this physicist accept Newton's Laws of Motion or does he only accept them when it suits him?