This was an Amazon purchase. The developer mentions Saturday, and how the Amazon review was left around the same time as the forum post, so presumably the the item was delivered on that same day. That's gonna be a bad experience for both sides: The purchaser has to wait until Monday to return, and the developer has to deal with (what I expect is) a drive-by flame. It's a Saturday night, and each side reacted poorly.
Honestly, I doubt the guy was going to continue attempting to use his device after leaving such a review, so the developer bricking it doesn't have any effect. In addition, the customer will get his money back via the Amazon return, so the developer was losing there anyway.
We don't know anything else, so I don't know what the actual problem would be. It could've been build quality, or shipping, or software, or the purchasers mobile device, or who knows what.
To be honest, based on what I see here, and speaking as someone who is just a customer, I believe the customer started the boulder running with his negative review and drive-by flame, and I feel lenient towards the developer.