Indeed, the evidence in the report hardly supports the conclusion. First trip for the guy in the front as PIC and having only logged 7 trips in the Super Tucano. So for his first crew solo he prepares and briefs with no supervision, crewed with a WSO who has only logged 5 hrs strapped to an ejection seat in his life and they get tasked to go off and fly a complex range sortie with heavy stores, EO asymmetric weapon drops and then some strafe!
If you think about the poor USAF guy in the back - a guy not familiar with dynamic aircraft or the encumbrance of a g-suit, helmet, mask et al and finds himself trying to log his 6th hour in the aircraft, head-down working an EO sensor, comms and GBU drop with a raw USN F/A-18 pilot in front on his first unsupervised sortie. He feels the aircraft depart controlled flight, looks up, is completely disorientated and finds himself looking at an unfamiliar cockpit and rapidly changing picture with a task-saturated pilot and no relevant training or experience to fall back on. I am amazed that he got out before impact and absolutely staggered that he and his pilot was there in the first place.
The Light Attack 'Experiment' seems to be with the aircrew rather than the aircraft or systems. The question seems to be 'can we grab random aircrew from any service, give them single-digit training hours on an unfamiliar aircraft type and send them off on a complex weapons profile'. The unsurprising answer is no, but the report manages to put all the blame on the crew.
The USAF really does suck at aircraft accident investigations.