A single byte change in the input changes the output. The sentence "Please do this for me" and "Please, do this for me" can lead to completely distinct output.
Given this, you can't treat it as deterministic even with temp 0 and fixed seed and no memory.
Well yeah of course changes in the input result in changes to the output, my only claim was that LLMs can be deterministic (ie to output exactly the same output each time for a given input) if set up correctly.
Let's eat grandma.
Interestingly, this is the mathematical definition of "chaotic behaviour"; minuscule changes in the input result in arbitrarily large differences in the output.
It can arise from perfectly deterministic rules... the Logistic Map with r=4, x(n+1) = 4*(1 - x(n)) is a classic.