'Show Dock' keyboard shortcut on a Mac bumps windows out of the way
I find this behavior strange. If you use the Mac keyboard shortcut to reveal a hidden dock (Cmd + Option + D), the appearance of the dock will 'push' any windows out of the way that are in the area where the dock appears.
Typing the keyboard shortcut again to hide the dock does not move the window back. This video hopefully demonstrates what I mean:


