Crossfire is a a massive issue. Never would you want to kill your buddy even if your trying to save him. So it is highly unlikely that you would full auto spray anywhere near him. You would take careful shots or not take them at all as he is better off alive than anything else, but fortunately olympus has a respawn button.
Perfect example is your riding around with some dude you kidnapped and some head ass decided to "save his buddy" he's going to dump a magazine into your moving car as if bullets do not bounce or go through objects and he is the best aim in the world, but untill the rule changes people are going to continue to do so.