I doubt a disagreement would make a person just walk out like that. My guess is that he just couldn't take it anymore, what ever it was, realized that there is nothing he can do about it other then to free himself from whatever it was.
the disagreement involved one of the rules I had for my daughter.
we lived in an area where things got stolen very easily...one blink and whoop there it went...okok, one blink with the back turned. So one of my rules was that before my daughter could play in the playground area, we had to first put her tricycle away (we lived right next to the park...and I mean right next to it). Once in a while she'd fight the rule, wanting what she wanted then and there instead of waiting a couple of minutes to put the tricycle away, but all in all, she was accepting the rule.
One day, the ISTj and I had been walking around the park following my daughter as she rode her tricycle. Then she decided she wanted to play in the playground area. So we started walking towards the apt so she could put the tricycle away. We had to walk somewhat past the playground to get to the apt. My daughter didn't start fussing until the ISTj asked weren't we going to the playground. I told him that we had to put her tricycle away. He said he'd take her to the playground and I could put it away. I said no, that I was trying to teach her to put her own toys away. Then he complained that she was too young to learn that (she was about 3yo). I told him that she'd been doing good about it so far. By this time, manta had either caught on to the possibility that she could get out of putting her trike away...or had somehow caught some thought that we wouldn't be going to the playground, and she threw one of her major hissy fits (aka screaming fits). So, now I'm stuck trying to calm her down, get the tricycle home, AND listen to him throwing things out of proportion (as if I was demanding she carry the trike upstairs herself!). ... Just as I finally get her to start pedaling home, he bodily lifts her out of the tricycle and carries her over to the playground. I was livid at that. But, I took the bike home and then went to the playground to play with my daughter. After she was done, we went to the apt, I told him I'd be right back, that I had to tuck her in, he stayed about halfway through my tucking her into bed, and then left just before I came back to the livingroom.
He didn't like my driving, so we had him drive my car.
He didn't care so much for my spontaneity, so I tried to tone it down and do a little more planning.
If there were other issues, he never brought them up to me, nor gave so much as a tiny clue.