Especially when they solve a complex (to me) problem with a very terse, matter-of-fact remark.
Sometimes I wonder if that isn't part of our Ti PoLR - an inability to see "the big picture" in one go. It's like having a multi-faceted diamond, I can only see one, two, perhaps three facets at a time. Everything looks promising, then you tilt the diamond a little and see the other facets, and it all looks bleak. At the worst, it all becomes one big tangle. ISTps seem to be good at summing things up. Without telling me what to do, trying and making up my mind for me, giving me a chilly cold-blooded Fi-less opinion that makes me slowly back out of the room, or thinking I'm merely being indecisive, inconsistent or dim.
Another thing about IEE-SLI duality: does that ever happen to anyone else? -- You tell an ISTp exactly what it is they're doing, and you're blunt, and they just grin as if they're thinking: "Yup, that's what I'm like, how wonderful that finally someone's GETTING it!" So you could say "come here and give us a hug, you sociopathic perfectionist you", and they'd take it as a compliment? (Bad example, probably..)