I'm not blaming the store per-se, just noting that the guy saw me leaving, and since I know he knows more than me about this, (and we both knew it was cold outside that night) he might have mentioned on exactly how I was taking it home.
With that said, that implies that the fish died from the cold temperature. Of course I can't make that determination, and no one will ever since, I was the one transporting him alone. Yet with what I've read and what other people have said such as piranapat, the fish literally could have been going into shock from being moved from the tank to the bag, and then the cold temperature or some other parameter beyond my understanding at this point, did it in.
Again, not asking for money back, but since it literally died from what I read should have been not that long of a trip for this fish, as soon as I entered my house, I just feel that a replacement fish for no charge is warranted, as it did not die from some unknown issue in my tank.