The question of what stage of the flight it was, which may be grounds for legal arguments.
I doubt there is going to be much in the way of legal arguments on this one, Boeing does not want to be anywhere near a jury. You can talk about the pilot's actions all that you want to, but ultimately you have two aircraft that were pointed to the ground at low altitude by a flight control system that was not disclosed to the pilots and that was (according to media reports) significantly different than the certification documentation described. Add in the cosy relationship with the FAA along with the whistleblower report and this is not something that goes to trial if Boeing has any competent lawyers left.
I am not a lawyer, but I don't think you ever want to be in a civil trial where the jury is wondering why the executives are not in jail yet.