Whether it's more complex than a state machine can model (doubtful[0]) and whether it "doesn't remotely reflect the biological complexity" may be true but the guy's point still stands, it's a mechanism that can be modelled.
non-determinism can also be modeled as a state-machine (and in fact, you can prove non-deterministic state machines can always be represented by deterministic state machines).
Ugh, you're right and I used completely the wrong terminology. I meant some degree of randomness (I think the posh term is stochastic-something), noise, jitter etc. Not NFA/DFA stuff. Good catch and thanks.
[0] you'd have to inject non-determinism as well.