I’m referring to the demo in the original article. The mouse pointer moves rather rapidly onto the inside of the window. You can just about see the resize pointer flashing as the user does so. I don’t think I ever attempted to resize a window with such erratic mouse movements. Approaching the corner at reasonable speed shows the resize pointer where expected.
Arguably the feedback via the cursor change is feedback to help you learn, like the icons that appear in the close / minimise / zoom, or stickers on the keys of a musical instrument. You pretty quickly learn which one is which, or you can't use them effectively. At some point you'd hope that common actions become muscle memory.
So if it was something that was learned whilst using the previous version, and worked, I'd argue it wasn't 'erratic'.
> I’m referring to the demo in the original article. The article from noheger.at? I am also referring to it. My guess is that the pointer speed is exaggerated due to zoom of the gif, and/or that we are using the mouse in different ways.