What worries me is this.
If the pilot wasn't aware he had lost part of the wing and part of the flight was conducted in VMC, then why was not this picked up on the lookout before commencing turns?
The number 1 rule of airmanship, is lookout. In a high wing A/C before a turn is initiated, the into turn wing should be "lifted" to make sure it is clear to turn. A level wing on a high wing A/C can mask a lot of airspace. So where was the pilot's lookout?