I did explain, and in detail. And I was going to include “Mac” in the guess, but passed in favor of brevity; point is you’re using a windowing OS on an Intel processor with color screen and mouse (or mimicking trackpad) - not a printing terminal or Braille display.
Oh, you gave an explanation all right, but you have absolutely no way of knowing that is what occurred and have offered absolutely nothing to back up your claims. You can't because you weren't there. Neither was I. There are a lot of things that could cause the flaws, not just what you explained.