Historically we run between a 12 and 15% fratricide rate on average.
http://www.carlisle.army.mil/usawc/Parameters/1995/steinweg.htm
Like car accidents, it happens. No one wants it and it’s regretful when it does, but it happens. Like a car which you need to get around but has the associated risk of an accident, fratricide is a simple reality of doing business as a soldier. You try to minimize it, but you can’t eliminate it unless you don't do what soldiers are supposed to do.
Issues like this are typically picked up on and distorted for political gain. Tillman was famous and his death controversial. We have over 3,000 dead and 20,000 wounded. His fate is special because politically some see a benefit in opening up this wound and pouring salt into it, rubbing it around, and pulling the bloody flesh back apart and asking "does this hurt?". Of course those doing this “care for the soldier”./sarc
Your comments are right on point.