I find it hard to believe that there was any kind of failure other than the human kind. They flew all the way to the USA from Dubai after nearly not getting airborne; if there was anything wrong with the aircraft, like UAS, DXB was just behind them for return. Information about how to go about flying is all in the manuals (FCTM especially) and I would be of the opinion that by the end of the flight they knew exactly what they’d done (or failed to do).
At least they didn’t try and reject at 220kts+ with <100m remaining; that would have likely got them into the top ten all-time air disaster list...