Ah. On landing. That's different then if it didn't scrape on takeoff and return to FNC. And if it's more common on landing, it's odd, but I stand corrected!
But surely the cartridge is there to absorb some impact? It's not just a green/red indicator. Also, the SP ones have a longer and bigger skid usually. Maybe it was an SP doing it's job?
Was it an SP with the nice SP kit?