You were under the impression that acrylic watch crystal don’t crack? If I am right about this “scratch” actually being a crack that extends downward, behind the bezel, then I’ll tell you that this type of crack on acrylic Rolex crystals is not a rare occurrence. However, it might appear that you know more about acrylic watch crystals than a guy who has been a watchmaker for 60 years, and a collector of Rolex watches for over 50! You appear to have come for advice, but you don’t accept it when it is given!