What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) Apparently the instructor allowed the student to pitch up to a higher than normal climb attitude after takeoff to demonstrate that excess airspeed would allow it. At about 70 mph the student was beginning to lower the pitch when "we encountered a wind shear, lost all wind, and the airplane stalled" (quote from the instructor). The airplane then broke to the left, was overcorrected, and rolled to the right, was corrected, and impacted the water/sand in a nose down condition. (The flight path resembled a falling leaf maneuver to witnesses). The impact site indicated the aircraft was descending almost vertically with very little forward movement. Both occupants exited the aircraft after impact.
As the FAA filed it
(-23) APPARENTLY THE INSTRUCTOR ALLOWED THE STUDENT TO PITCH UP TO A HIGHER THAN NORMAL CLIMB ATTITUDE AFTER TAKEOFF TO DEMONSTRATE THAT EXCESS AIRSPEED WOULD ALLOW IT. AT ABOUT 70 MPH THE STUDENT WAS BEGINNING TO LOWER THE PITCH WHEN "WE ENCOUNTERED A WIND SHEAR, LOST ALL WIND, AND THE AIRPLANE STALLED" (QUOTE FROM THE INSTRUCTOR). THE AIRPLANE THEN BROKE TO THE LEFT, WAS OVERCORRECTED, AND ROLLED TO THE RIGHT, WAS CORRECTED, AND IMPACTED THE WATER/SAND IN A NOSE DOWN CONDITION. (THE FLIGHT PATH RESEMBLED A FALLING LEAF MANEUVER TO WITNESSES). THE IMPACT SITE INDICATED THE AIRCRAFT WAS DESCENDING ALMOST VERTICALLY WITH VERY LITTLE FORWARD MOVEMENT. BOTH OCCUPANTS EXITED THE AIRCRAFT AFTER IMPACT.