There are other options. Remembering incorrectly. Being delusional. Etc. There's a difference. While he could be spouting lies, I think calling him a liar

There are other options. Remembering incorrectly. Being delusional. Etc. There's a difference. While he could be spouting lies, I think calling him a liar adds the idea that he has the intent to deceive, whereas he might not, but still inadverdantly spout lies. You may think my definition of liar is improper, but I think the nuanced difference is very important in everyday conversation.