That's not the problem though. The problem is that there's a layer on top of the flash which clicks still register to. There doesn't have to be a button at all,

That's not the problem though. The problem is that there's a layer on top of the flash which clicks still register to. There doesn't have to be a button at all, it just so happens that this example uses a button (controlled via javascript on this extra layer) that knows the pattern of where to click to allow the cam/mic to be used.