I suppose if you value your privacy over your well-being/existence you can perhaps resist giving up your password (not so with a fingerprint). Or maybe you could set up a "suicide pill" alternate password that wipes/bricks the machine when entered if you wanted to deprive your future self of the opportunity to relent as the torture escalates...
(Edit: I guess the latter is also doable via fingerprint if a different finger is used as the suicide pill, seems a bit risky for normal use though!)
It's actually quite simple and readily available with PAM duress [0] (at least on Linux, I'm not sure about PAM on Mac). It was also discussed here already [1]. Still, you should consider that doing so might not work in your favor, especially if the fact that you used a duress code becomes obvious.
Yeah it was more theoretical speculation, probably not doable on Mac (and I don't see Apple adding this feature tbh). I wouldn't be surprised if someone's implemented something like that in Linux though.
(Edit: I guess the latter is also doable via fingerprint if a different finger is used as the suicide pill, seems a bit risky for normal use though!)