At the risk of sparking off another round of to-ing and fro-ing, nobody's said that this guy did get to 60 degrees, so saying 'it was quite obviously aerobatic' is jumping the gun.
As previously mentioned, he apparently stuffed the engines by subjecting them to unusually long periods of low g - aerobatics not required to do that, just ignorance.
Perhaps any King Air drivers could elaborate on flight manual limits, warnings or notes that should have stopped him doing it, if he'd read and followed them?