It's not over yet. You were a witness. Expect to be harassed by insurance agencies, lawyers, law enforcement agencies, and the state department of transportation - and you might be sued yourself.
I know. I was a witness to a head-on collision a little over a year ago.
What ensued was an endless barrage of phone calls, affidavits, recorded testimonies, forms, and the multiple "oh we lost the recording of your previous interview, can we do it again" phone calls (designed to see if you changed your story), that amounted to nothing more than full-on harassment. I was even warned I might be named in one of the several pending lawsuits (I never was). I finally refused to cooperate any further; at which point the calls, emails, and snail mail finally stopped.
I felt really bad for the victims, but I also became a victim myself. Lesson learned. I won't be making the same mistake again.
Just thought I'd warn you for what's about to happen.