What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) After installing a new engine fuel system, a test flight was performed on the aircraft. Upon landing the nose wheel collapsed. After the aircraft slid off the right side of the runway, the right main gear also collapsed. The pilot stated that neither he nor the passenger remembers touching the gear handle after landing but that after the airplane came to rest the gear handle was in the up position. The aircraft owner said the gear selector detent had been inoperable for quite some time but that he had not experienced any uncommanded landing gear retractions or extensions.
As the FAA filed it
(-23) AFTER INSTALLING A NEW ENGINE FUEL SYSTEM, A TEST FLIGHT WAS PERFORMED ON THE AIRCRAFT. UPON LANDING THE NOSE WHEEL COLLAPSED. AFTER THE AIRCRAFT SLID OFF THE RIGHT SIDE OF THE RUNWAY, THE RIGHT MAIN GEAR ALSO COLLAPSED. THE PILOT STATED THAT NEITHER HE NOR THE PASSENGER REMEMBERS TOUCHING THE GEAR HANDLE AFTER LANDING BUT THAT AFTER THE AIRPLANE CAME TO REST THE GEAR HANDLE WAS IN THE UP POSITION. THE AIRCRAFT OWNER SAID THE GEAR SELECTOR DETENT HAD BEEN INOPERABLE FOR QUITE SOME TIME BUT THAT HE HAD NOT EXPERIENCED ANY UNCOMMANDED LANDING GEAR RETRACTIONS OR EXTENSIONS.