I've seen shows where they list things (etc rules, principles) with hitotsu for every point. I would expect hitotsu, futatsu... etc, to be the norm but it doesn't seem so. It didn't seem to be a running gag in the show I've watched for the char to mix things up or have short term memory, and I've seen it used more than once in diff places.
Is using hitotsu repeatedly just a way of starting a new point without having to go through the hassle of keeping track of the order and number of points being listed? In the same way we would probably just say "next point"?