@dalehileman,
Indeed, one should define "random" before proceeding. I don;t know what "purely random" means for instance. It's always a mix of chance and cause-and-effect, in my view.
All I am saying is that the idea a coin flip is
not random is a rather facile cliché, which nobody is able to prove. Determinism is reassuring for our rational mind, but that doesn't make it true. For all we know, the entire universe could be totally and utterly unpredictable, including coin tosses.