Everybody with half a brain knows it's never, ever a good idea to leave a little baby child in a car unattended, no matter what the circumstance. Excessive heat can be deadly and leaving the engine and AC on just increases the chance of your car being taken, baby included...not to mention the inherent risk of just leaving a child to fend for itself REGARDLESS of the setting.
But no matter how awful this woman is for leaving her baby in a car to buy a video game (and honestly, we couldn't have invented a better example of irresponsibility if we had all day), the guy who videotapes it is almost worse. Instead of calling for help or doing...well anything, he just videotapes on his phone and rants like an obnoxious do-gooder. But hey, maybe that's all you can do when "she done rolled up all da windows!"