There is nothing in these laws stating that the law of "keep left, pass right" is mutually exclusive of 'not exceeding the speed limit'. Your argument tries to follow some logic but is clearly not from the legislation. A road clearly has a maximum speed limit, if you choose to obey it and stay on the road (for as long as safely allowed) while some idiot in a Mercedes is flashing his light
and DRIVING RECKLESSLY, it may be easily argued that any change you make from your position may be dangerous, after all the driver behind you may be unstable mentally.