Run, sometimes I've said stuff like your OP mentioned when I just got frustrated and tired of trying to deal with raw logic, which is incredibly difficult for me. It's not that I didn't actually care, it's just that thinking that way was such a brain twist that I had to stop for a while, whether two days or two months.
Also, I don't know how your INFJ friend works, but I have a lot easier time when I can focus on one concept and study it, and then come back to an INTP and discuss it after I'm informed. INTP's run me around in circles and make me hate myself for my incompetence otherwise. I'm not good on my feet with that sort of thing. I need to really immerse myself in it before I can say something without making a fool of myself.