The minute I read about how the brother says he'll get justice one way or another, I thought threat to Greg, either then or much later in the season, when it's least expected.
But even if they drop that, with the way that Greg is, it is going to take it's toll, even if it happened by accident, even if it was in the act of saving a life, he's just so empathetic, my fear is that he'll internalize it, for not wanting to show the others just how much it bothers him, and it actually makes him lose that empathy, and that would not be good at all. I don't want to see Greg get so jaded that he becomes too serious, that even his jokes have an edge to them. I know all change comes, but still, there are those who just wish that that change didn't effect so harshly.
Also, where Greg, even though it was an accident, is a CSI and a death occured, and it wasn't a considered a natural causes death, there has to be an inquest.
From IMDB, just to see the "reporters" at the inquest, it will be a circus, and that just makes you feel for Greg even more, out of all of them, he's the least you would want to see or think would go through that at all, it's going to be one hell of a story arc, still, Eric is going to be just so SO good to see in this storyline.
One more thing, they can bring up favoritism all they want, but Doc would not risk his job or his professional reputation to cover up anything, so that alone should show the jurors he's telling the truth, but we all have seen that lawyers can turn anything around, and I bet the lawyers against will try to put some spin on all of them testifying.
The thing I'm looking forward to, how they, Nick and Sofia and Doc do testify for him, Greg sitting there, the amount of angst, and him being vindicated, even though Greg may still not feel the same after hearing the verdict though.