That accident report has nothing to do with the NZ accident.
Perhaps it has, this quote from the AAIB report
Synopsis
After a series of aerobatic manoeuvres the aircraft completed a stall turn and entered a vertical dive
from which it did not recover. Examination of the wreckage revealed the presence of a short-handled
flat bladed screwdriver that had jammed the elevator control such that the elevator control surface
could not be moved beyond neutral in the nose-up direction.
and this comment
A "stubby-type" screwdriver found in the wreckage of plane which crashed in Feilding last month, killing two men, may have caused the crash, investigators say............
.........The crash mirrored one in Britain in 2003 which also claimed two lives; a stubby-type screwdriver became lodge in the tail of the Yak 52 aircraft in that crash, affecting its controls.