We don't know if that was the Enterprise crashing. It could be any Starfleet Constitution Class Starship.
I was thinking, that "Hand shot" could even be Cumberbatch himself. If he is Mitchell, and the writers adhere to some part of original timeline, then Kirk and Mitchell were best friends until Mitchell is altered/driven mad by Psi-powers, and Kirk has to reluctantly kill him to save his crew. So it could be something similar to that. Or not. LOL!
Maybe it is Chris Pike. That would make sense too. Kirk's father figure, his only real family, murdered by the villain, forcing him to fully embrace his destiny. It is classic Hero Journey stuff.
It just better not be Spock. I think that would be taking the Khan homage too far.
Plus, for the relaunching of a rebooted franchise, it just seems like a bad idea to me as I am sure Paramount wants to get a couple more movies out of these actors.