I had a chance to look at purported crash footage.
I think this was pilot error.
This said, given that the 787 is fully FBW, it is entirely possible that the flight control laws were faulty, with the flight control computers (FCC) sending the wrong signals to the engine's full authority digital engine controllers (FADEC). Ironically, much Boeing flight control law coding is done by endentured H1B slaves, while niggers build the aircraft.
But, the most likely scenario is that they could have taken off with the wrong flap settings, where, even with the engines at full power, the aircraft was unable to climb, leading to a stall. Looking at the video, my money is on this.
https://youtube.com/shorts/2_iRyAQn7Nk