Urgh, no sir, I don't like this one.
Go read this:
http://www.salon.com/2014/06/03/the_day_i_left_my_son_in_the_car/
The digest version: This mom left her son in the car at his repeated insistence as she dipped into a store, in clear conscience of every variable. It was daylight, her car was in a safe, visible area, the windows were cracked. She went in for one item, as planned, and came right back out.
In this speck of time, someone saw the kid and called 911.
The cops showed up on her doorstep shortly after and she was thrust into a years-long nightmare scenario of financial penalty and moral browbeating. Y'see, in the eyes of the law, the person that leaves their kid in the car for a minute with care taken that they are safe is every bit the same reprehensible scourge of parental villainy as the one who leaves their kid in an airtight deathtrap for hours.
Which is patently absurd.
So your rule wants for some interpretation, in lieu of the lack of it allowed by the law. Does the kid look uncomfortable? Are the conditions severe? Have you, personally, observed the child left alone for any vaguely unreasonable extended period of time, or are you immediately assuming it upon first sight, with no reason or evidence given? Why are you eager to tie up and hassle everyone involved with a initiating a 911 dispatch, but unwilling to even entertain the notion of approaching the car to take one damn second to ask the functioning human being inside if they're OK, and potentially avoiding the whole situation altogether?
The very act of leaving a child in a car is not inherently negligent. Your parents probably left you in a car, once or thrice upon a time. Do you wish that some 'good samaritan' had come along in those moments, sicced the dogs of justice upon them, and dragged them through the streets for their malfeasance?