Tire deflation after shooting it does not work the way it does in the movies. It deflates very slowly (the rubber closes behind the bullet). You can keep driving for a long time after a bullet goes into the tire. Oh, I am just guessing, of course.
It's quite possible that he hit the wheel and not the tire. More importantly, did anyone notice that he was shooting at fleeing perps of a misdemeanor (or NON-forceable felony at best)? Can't you go to jail for that?
That's not been my experience. When you take the valve stem out of a tire (which is about 3/16" across) the tire will be FLAT in about 15 seconds. A 9mm hollow point should leave nearly twice as big a hole in the tire as the valve stem, perhaps two holes if it makes it out the other side. I would imagine a shot tire would go down in less than five seconds. That being said, you can drive a surprising distance at substantial speed on a flat, (maybe a few miles if you're running scared)
UTAH CODE Section 76-2-406 76-2-406. Force in defense of property. A person is justified in using force, other than deadly force, against another when and to the extent that he reasonably believes that force is necessary to prevent or terminate criminal interference with real property or personal property: (1) Lawfully in his possession; or (2) Lawfully in the possession of a member of his immediate family; or (3) Belonging to a person whose property he has a legal duty to protect. Enacted by Chapter 196, 1973 General Session Maybe the explanation of why the roommates shot at the vehicle's tires instead of into the passenger compartment, and why he wasn't arrested after the shoot, are contained in this UT statute? Those boys may have been been better versed in the laws of their land than it initially seemed.
But, the way the article reads, the perps had already stopped the "criminal interference with real property or personal property" and were just getting the heck out of there. Secondly, it has been my understanding that discharge of a firearm IS deadly force and that the law makes no distinction about whether you were going for a head-shot, a foot-shot, or a tire-shot.
Your first point may have merit; but I'm not so sure about the second. Above all else, it doesn't appear the boys were arrested, which is good. After all, no matter what the letter says, the law is only as strong as the will of those that enforce it.