What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) On Sunday, March 18, flight #303, DHC-6-300 N331SA, exited the runway about 50 feet to the right at Monument Valley Airport (71V). There was no damage to the aircraft and no injuries to passengers or crew. It appears that the SIC simply lost control near the end of the landing rollout, most likely after selecting reverse power, where there is a possibility of an uneven engine spool-up.
As the FAA filed it
(-23) ON SUNDAY, MARCH 18, FLIGHT #303, DHC-6-300 N331SA, EXITED THE RUNWAY ABOUT 50 FEET TO THE RIGHT AT MONUMENT VALLEY AIRPORT (71V). THERE WAS NO DAMAGE TO THE AIRCRAFT AND NO INJURIES TO PASSENGERS OR CREW. IT APPEARS THAT THE SIC SIMPLY LOST CONTROL NEAR THE END OF THE LANDING ROLLOUT, MOST LIKELY AFTER SELECTING REVERSE POWER, WHERE THERE IS A POSSIBILITY OF AN UNEVEN ENGINE SPOOL-UP.