You have to understand one thing though. Even if you say it is a freekill, it very well might not be. Think about this for a moment, if a T is running directly at you, even though they are not knifing, would you shoot them? I know I would because first of all, I am taking that as a hostile threat against me, and they cannot be following the orders while trying to run at a CT. If you truly were freekilled, just simply report it the admins with the @ in team chat saying something along the lines of "Hey, BillyClank freekilled me, do you guys mind keeping an eye on him? Thanks." More than likely, you will get a response from an admin confirming that they will keep an eye out, if not do not worry about it. The admins have a lot going on that =(e)=? members and pubs cannot see. So even if it does not appear we are they, rest assured that we are.
Last thing to keep in mind, this is jail. Jail at times can be near if not full, so a lot of people can easily get confused so accidental kills may happen. In the instance of a rebel, crossfire may happen. Just remember that everyone is human and we all make mistakes at one point. I know I have had my fair share of accidental freekills, but the best thing you can do is to let the admins know, move on, keep in mind its a game and you will respawn next round.