That's kinda weird. The "little finger" part of the gasket---that should have been covered by the base of the water pump, right? If that's the case, how could it have bent out like that, scraping the blades?
Are you sure that finger didn't just stick to the pump when it was removed, bending outward at that point? Of course, if that's the case, it's hard to explain the grinding down of the impeller blades.
