After watching a few seasons of traitors (UK) I feel none of these techniques work and may even end up accusing the wrong person.

The show had former detectives and police folks failing miserably. It just boils down to evidence.

These don't work for very good liars. They know all these tricks, often intuitively, and purposefully avoid them. The only strategy that works is listening to your gut and extending trust slowly. Keeping up a ruse is tiring and the more time you give them, the more chance they have to make a mistake. Combine that with listening to the brain in your gut that has evolved for millions of years to sense danger. In the early stages, the mistakes are often subtle and you will usually only get a feeling that something is "off".

Good liars are able to avoid these tells and I reckon no system is perfect but the last point, trusting your gut, is probably the best as it combines a lot of conscious and subconscious observations into a judgement. I'm often unable to articulate why I trust or distrust a person but feedback from my close friends is that they'll look to me for signs about a new person we meet. You do also need to be willing to constant reevaluate and change opinions as more evidence is gathered.

In my experience, an indicator that my interlocutor is (possibly) lying/BSing, when challenged for an explanation for something they did, is that they provide a list of reasons. The person who's telling the truth just gives one.

OK but most liars don’t fabricate an entire story.

In the startup world they might claim to have 1.5x the rev they have, or that an impressive logo is trialling their product when really they’re in early talks, etc…

Then it’s much easier to tell the “truth” with one twist and these methods fail.

While I understand the importance of "trusting your gut", I feel uneasy about telling people to just go with it because that's how you entrench confirmation biases: you don't know what's driving your judgement, you don't need evidence (in fact, you can now disregard it), and you have no way to assess the accuracy of that feeling except in those rare cases when you find out you were right.

Sometimes your brain picks up that a person is dangerous in ways your rational mind cannot explain and you'd be thankful that you follow that feeling. But also sometimes your brain dislikes minorities in ways you're not comfortable accepting and now you're actively being part of the problem.

Can't help but notice that Musk uses all of the techniques.