It doesn't "lie" though, it just generates a plausible sequence of words. The sort-of fortunate thing is that facts are often plausible, and it's going to be trained on a lot of facts. But, facts aren't the only word-sequences that are plausible, and LLMs are trained to be creative, and that means sometimes choosing a next-word that isn't the best fit, which might end up meaning the generated sentence isn't factual.

Calling it a "lie" suggests that it knows the truth, or that it is being deceptive. But, that's giving "spicy autocomplete" too much credit. It simply generates word salads that may or may not contain truths.