Sure it does. Fidgeters are liars. Fidgeters are not people who just fidget.
Why can't there be both people who fidget in general and people who fidget only when lying? Is that not a thing?
You specifically said "he's fidgeting, which is indicative of lying."
In the case of that
specific NPC in the example after a
successful Wisdom (Insight) check to reveal that NPC's lack of truthfulness, yes. I also said the NPC was stammering in the example you're misconstruing and using to obfuscate. Not a good look in my view.
You: This guy is fidgeting and he says blah.
Me: <not remembering that for you, fidgeting means liar> Um, OK?
Other people: Wait, he's fidgeting? I roll Insight!
Again, you're asserting something I did not say and twisting my words to suggest something I don't believe. That is not cool.
As well, nobody at my table would say they're "rolling Insight." Players don't ask to make ability checks. Plus, isn't that sort of acting out of character since they aren't declaring actions from the perspective of their characters in the context of the game world? That seems rather immersion-breaking for those of us (like you and me) who care about immersing themselves in the game. Is that what they do at
your table? If so, I'd like to hear more about how you're able to maintain immersion with that sort of thing, but not when someone chooses not to have their character act intimidated in a way that is inconsistent with previously established characterization.
In any case, I noticed you didn't address how your character is disadvantaged by this. There's still nothing stopping you from making the very same attempted action as the "other people" in your example. So again, what has changed for your poor character here? That you didn't think to say "I roll Insight!" first? Is there a metagame competition going on at your table for who asked to roll first? I've done something like that before, but for claiming Inspiration and it can be fun. (But just for that particular one-shot as it reinforced a theme in the actual adventure.)
Clearly you rolled a nat 1 on your Insight check, then.
Luckily my ability score bonus and proficiency bonus more than make up for it.
