While I'm not much of a (good) liar as an Aspie, I have been known to exaggerate here and there. And yes that does sound a bit like Mr. Spock in the Wrath of Khan, if I might sound just a tad geeky
However, I would have to say that by and large exaggeration is an NT behaviour. When they say things like "oh man, this whole thing is gonna be the end of me" or "I must have told him this like 200 times" - yeah...that can be somewhat annoying. It's always with a melodramatic or commiserating edge, of course, and I partook of some of it too - but not nearly to the same extent. What bothers me though is that when I'm the subject of the exaggerated remark. One time in a meeting at an old office job, a co-worker was making a statement about some aspect of a project, there were about 12 people present in the room, and she turned to me and explained that the statement really meant such-and-such (which I sort of thought it did, but wasn't 100% sure) - then followed it with the snide comment "I have to explain that to you Jayo, because I know you take everything literally." This prompted some laughter from a couple of meeting members who obviously knew about my "nuance dyslexia" and while I was tempted to respond "that was uncalled for, I don't take everything literally" - I know she would just say "see, I didn't mean literally everything, I was just exaggerating". So I held in my anger and just shrugged it off.