My INTP husband sometimes say things backwards or the exact opposite of what he means. This is often when he's telling me a story. I can catch his meaning, but it's come out all wrong. This is puzzling, given the fact that INTPs are supposed to use such precise language.
He can also be very imprecise about time, amounts, etc. Eg, how many hours did a job take? "Three. Or five. Or Two." Wait - isn't five hours more than twice as long as two hours? He'll often throw out random numbers that are off by a factor of two or three instead of saying "I don't know."
The ENTPs I know don't have this problem. They just say "I don't know." And they don't use backwards/opposite speak.