If We'da Aimed At Ya, We'd a Hit Ya, and Ya'd be Dett!
First of all, for all the people that don't know, the US Military uses a type of machine gun that fires .50-caliber ammunition. IF you don't understand that, that means that the slug is a half-inch across (diameter). It's also about an inch and a half long. It's travelling at about 2250 feet per second when it leaves the muzzle of the machine gun, and it can be fired at a cycling rate of up to 1200 rounds per minute (usual rate of fire is lower, around 660 rounds a minute, I believe). These aren't made of lead, but very hard steel or another alloy. They make BIG holes in things, and will penetrate up to five inches into the block of a V-8 engine in a gas-guzzling SUV. They will pass completely through one side of a vehicle, through anything in between (including bodies), and exit the other side, unless it's an armored vehicle. It'll go completely through a half-inch piece of steel plate, if it's fired on at a close enough distance.
The ordinary grunt is probably carrying an M-16, which fires a very high-velocity but small slug. The M-16 fires a 5.56mm round, which is smaller in diameter than a pencil. It fires it at a very high muzzle velocity, however, so that it hits with considerable power (The kinetic energy of a bullet is calculated using the formula K=mv, where m equals the mass of the bullet, and v equals its velocity, or the speed it's travelling. Increasing the mass or the velocity either one will increase the impact energy). Most of the weapons I've seen in photos or on television also seem to be equipped with a grenade launcher. Catching one of those in the windshield will ruin the entire day for everyone in the vehicle.
The purpose of any real military is to exert controlled violence to achieve a stated objective. The objective is NEVER to do a halfway job. The other thing to remember is that there is only ONE "chain of command" - and it doesn't include outsiders. Orders are always passed down the chain of command. The wishes and desires of others is immaterial. Failing to obey a lawful order is grounds to get someone hung, and the military still has the legal ability to hang people.
The United States military establishment is the best-trained, most professional force in the world. Everyone that's a part of it is a volunteer - they're there because they want to be. They've been given the best weapons money can buy, and the best training ever given to a military force. There's also a heavy helping of mutual support and dependence. No one wants their best friend hurt, and no one wants to get hurt themselves. They'll do whatever it takes to see those things don't happen.
I spent many of my formative years in Louisiana, where there are more different kinds of stinging, biting, and just plain nasty creatures than just about anywhere else in the United States. I learned at an early age that stirring a hornet's nest, or digging into a fire ant's mound, was not a wise thing to do. Apparently the people in the car with what's-her-name didn't have those early childhood memories to protect them from doing something incredibly stupid.
Just saw the photos of the car on Captain's Quarters. I spent more than 20 years interpreting reconnaissance imagery for the US Air Force. This car was not attacked by "indiscriminate firing". Nor was it attacked by a machine gun of any kind. A machine gun, especially a M-60 machine gun, leaves a very definite pattern of bulletholes in anything. There is no evidence this vehicle was hit by more than a dozen or so rounds of ANY kind of fire.
If you live near a military establishment of any kind, ask the Public Relations officer (every base has one) if you can watch a live-fire exercise. You'll learn very quickly that US firepower is both lethal and NASTY. That vehicle was not subjected to the kind of firepower that commieslamofascist nutjob is insinuating happened. As I said up above, if she had been, she'd be dead, and so would have been everyone else in the car.
I'm pretty sure that the driver didn't expect the (temporary) checkpoint to be there, didn't react appropriately to it, and got the shock of his/her life as a result. It's a pity it ended in someone's death, but that was caused by the Italian driver NOT doing HIS job, and the US Military doing its.