The trespasser was committing a property crime outside of the house, making no effort to come into the house. From your description, there was no indication that the trespasser was armed, nor is there any reasonable basis to assume that an a-hole breaking into cars in driveways is armed.
The trespasser would not deserve to die for turning around, absent the shooter’s reasonable belief of his own imminent harm, such as trespasser showing a weapon or charging the homeowner.
So if the homeowner shot and killed the trespasser for the simple act of turning around in violation of “the order,” the homeowner should be subject to prosecution for manslaughter. OBVI.
Chickenshits don’t get to kill people in the circumstance you describe...but I notice you gun nuts are chickenshits so you’re probably ok with it. The “order” makes you feel powerful. I get it.