Science hates this kind of free choice equivocation because it leaves open the possibility of a religious transcendent and mystical free choice. Although Religion just like Science assumes that we live in a mostly causal universe, religion further believes that there are also some transcendent precursors that we can never know about for some outcomes like free choice. Ellis argues against any transcendence and instead argues that it is biological complexity that precludes knowing about all precursors to free choice outcomes. In fact, Ellis does not even mention the religious narrative that attributes free choice precursors to transcendent mysteries. Ellis does conclude his essay by stating his belief that without free choice, we would not have moral responsibility and so he is glad that we do have free choice and therefore moral responsibility.
Both Ellis and Science presume that we live in a causal universe where every outcome has a set of precursors. A precursor for each outcome then means that there are no transcendent precursors from outside of the universe. Naturally, then, since every outcome has precursors, Science argues that we can in principle know the precursors of any free choice outcome as actually determinate and not free. Ellis argues that it is biological complexity and molecular uncertainty that preclude any knowledge of free choice precursors. Many others in science believe likewise that the complexity of random chaos similarly precludes knowing about all precursors to free choice outcomes.
Even though we do live in a causal universe where there are precursors for every outcome, that simple fact does not then mean that we can know every precursor. In fact, there are many unknowable precursors for outcomes that we readily admit to. Why are we here? Why are we here right here right now and not at some other outcome? Why is it us who are right here right now and not someone else? Why is the universe that way that it is? Why is matter the way that it is? Why does action change matter the way that it does?
These are all perfectly reasonable questions that have no answers and are part of what we cannot ever know about the universe. Science calls such questions meaningless since they do not have measurable precursors, but religion calls such questions transcendent because their answers lie outside of the causal universe. One argument about free choice is that a machine does not have free choice and even a really complex machine only does what its creator programmed it to do. The argument continues that a creator is also just a machine that does what their creator programmed them to do, and so on until the transcendent master simulator of creation. This means that we are all in a determinate simulation of the Big Bang and have no free choice at all.
Science does accept that it is impossible to predict the outcome of free choice from its precursors even though Science cannot either define or measure free choice. However, then Science goes on to list all the of reasons that make the precursors of free choice unknowable. Science then concludes that even though Science cannot predict free choice outcomes that does not mean free choice exists, just that we have the illusion that free choice exists in a determinate universe.
However, there is no measurement that proves free choice outcomes are illusions, the free choice outcome does not depend on whether you believe in free choice or you believe in the illusion of free choice. Therefore it is simply impossible for science to address free choice without a measurement or even a definition of free choice.
Ellis rightly decries the moral relativism that results from a lack of free choice. Thus, he is relieved that there is free choice even though he does not define or measure free choice.