What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
The PIC stated that he had entered the aerobatic box located near the Eau Claire, WI (keau) airport to practice his aerobatic routine. After the aerobatic routine was complete, he returned to keau to land on runway 22. After landing, the PIC stated he tapped the brakes. When he did this the left brake would not release pressure. Subsequently the aircraft slowed and pulled to the left until it departed the runway into the grass at slow speed. The PIC indicated that there ws no damage to the aircraft and no injuries. The PIC found that the parking brake had come out of the locked (off) position sometime during the flight.
As the FAA filed it
THE PIC STATED THAT HE HAD ENTERED THE AEROBATIC BOX LOCATED NEAR THE EAU CLAIRE, WI (KEAU) AIRPORT TO PRACTICE HIS AEROBATIC ROUTINE. AFTER THE AEROBATIC ROUTINE WAS COMPLETE, HE RETURNED TO KEAU TO LAND ON RUNWAY 22. AFTER LANDING, THE PIC STATED HE TAPPED THE BRAKES. WHEN HE DID THIS THE LEFT BRAKE WOULD NOT RELEASE PRESSURE. SUBSEQUENTLY THE AIRCRAFT SLOWED AND PULLED TO THE LEFT UNTIL IT DEPARTED THE RUNWAY INTO THE GRASS AT SLOW SPEED. THE PIC INDICATED THAT THERE WS NO DAMAGE TO THE AIRCRAFT AND NO INJURIES. THE PIC FOUND THAT THE PARKING BRAKE HAD COME OUT OF THE LOCKED (OFF) POSITION SOMETIME DURING THE FLIGHT.