As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PASSING FL 180 A LOUD BANG WAS HEARD FOLLOWED BY THE HANDLE MOVING ON THE R2 WINDOW. THE INDICATOR WAS BETWEEN OPEN/CLOSED. R&R R2 WINDOW AND ACCOMPLISHED ADJUSTMENT PER AMM 56-11-02. PRESSURIZED AIRCRAFT PER AMM 21-31-00. NO LEAKS NOTED.