I too have had my fair share of 'whistlers'. Given the large number of airdrops I participated in it would be surprising if I had not. Apart from parachute malfunctions material failures spring to mind as the cause on several. I have never had a drop where the load freed itself from the platform. Not even when on JATE. I have had several premature drops where the parachute disconnects did not work 'as it says on the tin' and allowed the parachutes to part company with the load before the load reached terra firma. All in all my recollection is that the whole system was pretty reliable.