Blame is primarily on Reynas, but if Berhalter never opened his mouth after the tourney, then there is good chance none of this comes out. Berhalter decided to get back at the Reynas through the media, which is on him. I'm not sure any of this public fallout occurs without that Berhalter interview. Berhalter would be hurt/pissed, but that would be the extent of it.
No one looked good in this, but I think there is no way that Berhalter could or should be the coach. He never should have mentioned the issue with Gio in public if, as he said, the team dealt with it internally. Also, I cannot fathom for the life of me why you would tell a young, but very talented player, that they were not really going to play a role in a tournament. Aside from de-incentivizing a young player (rightly or wrongly), tournament play is very hard to predict and presumably he selected his roster with everyone having a role to play. It was just a conceivable because of injury and/or poor play, Gio could have played a larger role. I also think he is not the right man for the job, notwithstanding I think he performed far better that I would have expected (granted, I had very low expectations).
I think the Reynas were way, way off the reservation, however, as a father myself I can see the desire to protect their son from being publicly pillared. I can also see the argument that mistakes made as a young person should not necessarily taint you in the future. There is some hypocrisy with respect to Berhalter's conduct with respect to his wife in college and his redemption and calling out Gio for far less conduct. Notwithstanding that, it was cruel to Berhalter's wife to rehash what was undoubtedly a highly traumatic personal incident. I am not one to say that it is water under the bridge, because I do not believe domestic abuse can ever be forgotten. Nonetheless, I do believe in redemption and forgiveness and I also believe that it was Rosalind Berhalter's decision on how and when to forgive and forget.