It all starts with the parents. They have been trying to downplay and sweep it under the rug since day one. I recall reading the police report back when the story first broke a couple years ago. The Millers were essentially refusing to cooperate, the Dad tried to chalk it up as general horseplay aka boys being boys. Of course a kid is never going to properly comprehend his actions or feel remorse, if mom and dad are patting him on the back telling him it wasn't that bad.
That attitude is what made almost every team put him on their do not draft list, more so than the incident itself. If he was truly ashamed, and had made efforts to make amends because it's the right thing to do - this story would essentially be over by now, in terms of having been able to move on with his career.
But the prevailing take away from teams was that he says what he thinks he needs to say in order to minimize and try to get past it for his own benefit. The family to this day, still just aren't getting it. Dad on twitter liking and retweeting comments that refer the incident being exaggerated. Sister tweeting videos of the victim attempting to sway public opinion of his character.