I'm an ISTJ, and I can pick apart most flaws in an argument or conversation, as well as really twisting the words right out of a persons mouth. I can't think of any specific examples, but I use it mostly for fun. I take an innoculous bit of conversation, mess with it, and send them on spirals of justifications before they catch on. I wanted to know if this were an SJ thing, or just something personal.
EDIT: Also, picking out the flaws in arguments or papers no matter how inane, is something i'm good at. Generally, I am a good person to run argumentative papers by.