He said, she said... yadda, yadda, yadda
They just didnt test properly or comply with the ASTM requirements.
I served on the F37 committee for about 4 years and know shortcuts taken by some manufacturers because they used to stupidly boast about them, including signing off other model variants (nosewheel versus tailwheel, short wing versus long wing etc) because they just didnt want to do the work. Many also tested spinning at the 472.5 kgs European limit and then declared compliance at 600 kgs without any additional testing.
There are 600 test points as part of proper spin and recovery testing and each must be completed 3 times safely.
I cant post the requirements here for ASTM copyright reasons.
Lest just say, regardless of who was flying the plane during testing that this any many other manufacturers didn't meet the testing requirements for spinning and many other requirements and this is a big issue with manufacturer self-validation. The manufacturer can say anything up until they are asked to validate the compliance with the standards and the problem comes when they cant validate as has happened here.