This would require making a suggestion to update the rules - which you can do in the Suggestions section.
My opinion (Not as staff) - Crossfire is accidental, its not done with the intention of harming teammates - its done with the intention of harming enemies and only enemies. If you are in a situation where your behind someone they are trying to shoot or walk into the line of fire - I don't see why the person shooting should be punished. Bullets go through people, they move or lag occurs - all examples of Crossfire.