BGring - a vital point you have left out is that the root of the retreating blade is not producing useful lift at all - it is in an area of reverse flow. Therefore the remaining area of the blade on the retreating stall has to operate at higher angles of attack to equalise the lift across the rotor disc.
You imply that the tip stalls first - contrary to what you would expect - this is not so because the root and inboard section have already ceased to produce lift and are in varying degrees of stall; this causes the blade to flap down and increase the AoA to a point where eventually the tip stalls. At this point there is very little of the blade producing anything but drag and vibration and the classic 'pitch up and roll towards the retreating side' occurs.
The stall angle of the aerofoil may well change at higher speeds but we are talking about the low speed side of the disc so that argument is inapplicable. More modern helicopters use aerofoil sections other than the 'standard' symmetrical aerofoil section and some have different sections along the length of the blade to reduce pitching moments and improve performance.
Quite why you see RBS as a 'failure', I don't understand, as no system or component on the helo has failed - it has just reached an environmental operating limit - change the environment and normal service is resumed on the rotor.
The language used in the article is not 'explanation friendly' and uses some inappropriate words and phrases more likely to be found in an academic or engineering book than a flight manual.
The quoted source is an FAA Basic Helicopter Handbook but I would be surprised if it says exactly (or even close to) what has been put in the RBS article.