1. the slope of self-perceived ability is lower than actual ability
2. The y intercept is dependent on difficulty of test
Therefore with an easier test the better testies are more accurate, and with a very difficult test the worse testies are more accurate because of where the lines intersect. Meaning DK is artifact of test difficulty.
This also means if the test was difficult enough you could create a bizarro-DK effect where the better testies were less accurate.
For 2, the DK paper shows one thing, but the replication attempts have show this effect doesn’t even exist for very complex tasks, like being an engineer or lawyer. The DK effect doesn’t generalize, and doesn’t even measure exactly what it claims to measure, which is why we don’t need to speculate about the bizarro-DK reversal effect - we already have evidence that it doesn’t happen, and we already have a big enough problem with people mistakenly believing that DK showed an inverse correlation between confidence and competence, when they did no such thing.