That is something an admin would be better to answer... RVD is more something of intentionally blowing up vehicle as RDM is RANDOM death match...i would think if your aiming at a car and they swerve and you hit a quad bike and guy behind him you would be ok as there is nothing random about the death, just wrong place at the wrong time...but I would get a mod or admin to confirm that one..
But what I can tell you is that if you fire a RPG at someone near a restrained guy trying to free him, even though he was "crossfire" you will still get banned for fail rp because you had to know you were going to kill the guy in restraints too, same with chucking grenades, sui vests, etc at guys in restraints with a cop or vigi near by...