The logic you continually try to assert takes no account of the ability for our conscious awareness to exert conscious control from its own state, not from the pre existing state of our material brain.
Which changes nothing about the logic. Either this state of conscious awareness is behaving as a deterministic system or it isn't (and therefore involves randomness). As I've pointed out many, many times, the logic has nothing to do with the material universe.
As your conscious state changes over time, does it do so entirely because of reasons, or partly due to no reason?
The capabilities of our conscious awareness provide the definitive difference between choice and reaction.
Those would be the capabilities that you can't define and the supposed difference between choice and reaction, that you also can't define. So not very definitive, really.