On the way home from work I was thinking about the OP in this thread. It struck me that a few things don't add up. The SG left the dog in a closed up car in a parking lot in FL. When they came back, no dog. No mention in the OP was made about anyone leaving a note on the car, so it may or may not have happened. The SG then drove off without inquiring about the dogs health or location.
What hit me is that it sounds like the SG was more than an SG and may have actually been TRYING to "get rid" of the dog.

As in, gee, I got ex's favorite beast in the divorce. Then tries to do the "I don't know what happened, he just fell over" (while trying to look totally innocent).
This possability would push me from just being angry that an SG could be so stupid (I know, redundant), to furious that someone could be so dispicably evil. I would hope that the local LEOs would investigate a bit and see if the SG needs to get an endangerment fine for being stupid, or needs jail time for being so deliberately evil.
And in either case I would make sure (with a rusty dull knife) that this SG would never procreate. The same thing could easily happen to any child of theirs.
JMHO
Randy