This is incredibly tough. I've found that if they can't go at least a bit more in depth about whatever it is, or if they can't point to relevant examples of wha

This is incredibly tough. I've found that if they can't go at least a bit more in depth about whatever it is, or if they can't point to relevant examples of whatever they're talking about, that can be an indicator of them being full of it -- however, this isn't enough to make me suspicious unless it happens fairly often, and if it was from an area I had absolutely zero domain knowledge of it would probably be fairly easy to fake as well, if a bit more rare for people to do so. Other than having people that you know are competent in X, or studying up on X to the point where you can start to smell bullshit, I'm not aware of any sort of really reliable techniques. People who lie a lot tend to suss themselves out over time, but that doesn't mean they haven't cost everyone a lot of time and money by the time they do. Maybe some of the body language indicators could serve as an additional "hmm seems like this person might be full of it" -- blinking more, looking up and away, etc. These are also not reliable as a steadfast rule though, especially in fields that are filled with introverted left-brainers, ha. It'll be interesting to see if anyone has any decent techniques for this.