[dreamcompiler]

MacOS has had a similar issue as far back as 10.7. In 10.6 and before if you see a window with red, green, and yellow buttons in the corner, that window has focus, period. It was an enforced invariant.

In later versions it's pretty common to see such windows that don't actually have focus. Clicking again on the title bar usually fixes the problem but I find it very annoying. There's a race condition in the system somewhere that Apple doesn't recognize as a bug.