Firstly, the first thing isn't a myth, it happened quite a few times in the computer shop back when I first started working there, which was before that card was released (actually, before R520 was released at all, let alone that card.)...and most of the computers we worked on were already at the VERY least a year older than new stuff at that time. We're talking between R100 and R300 (the first Radeons), and the Rage series. We're also talking about fresh installs, sometimes with no IGP to start with, just a chipset driver.
As for Hybrid, I haven't seen anything "new" about it. The original Hybrid that I was talking about was solely for certain AMD 700 and 800 chipsets. I know there's a newer thing now with the A6 and A8 APUs with a couple HD6xxx cards, but it's called "Dual Graphic" or something now. So I guess that's "new" technically, but I was specifically speaking of a time when APUs weren't on the market, like this guy's computer.