The question that will never be answered is why the aircraft pitched up to 45/50 degrees after lift off, forget vertical. Some unknown event caused this.
,
That statement is correct, it will never be known with certainty. But I can say, after some 7,000 hrs flying FU24 on Ag Ops, with many thousands of t/o's, that the behaviour of the aircraft immediately after t/o points very strongly to the trim being left in the landing position and not set for t/o.