I didn't read the previous thread so I don't know HOW the screen broke, but it may not be explicitly his fault (stupidly putting an expensive system in his pocket aside).
My sister had the screen on her phone crack recently of NO fault of her own. She walked from the parking lot of a store, phone was fine, she entered the store, about 2 minutes into walking around the store, she gets a text, checks her phone, screen has a crack clear down the middle of it. We're thinking it had something to do with going from cold to warm, but we're really not 100% sure on what the hell happened. The crack was definitely not something she could inflict herself, that phone could take a hell of a lot of abuse without even denting or scratching.
So it's not exactly 100% obviously his fault, unless i'm missing something by being too lazy to check the previous thread.
and frankly while I don't see anything right with what he did, I agree with Soulx for once. It may not be an Apple product, where a practice such as this is perfectly fine and very encourageable, because fuck Apple. $130 is likely a hell of a lot more money to him, than it is to Sony, and Kmart doesn't take a loss for it being 'defective'.
Though OP is a bit of a retard for just saying it wont turn on. I mean, hey Derpenstein they generally take down your info and record WHAT IS WRONG. So if it's inspected and they go "the fuck is this crack, this should just not turn on" they're going to bust your kneecaps in with a spiked baseball bat.
But if kmart is anything like walmart in regards to returns, everyone is underpaid and no one fucking cares at all.