1) Those nicks on the left in the picture are small but noticeable, but I honestly don't really see a ding. If it's just in that one spot, I'm not sure how it would have happened from being slammed down flat on it's back, unless there was something on the table that hit it (would have to be an extremely small piece of something though).
2. I have to agree with Applejuiced, how did no one else in the store notice this? Surely other employees would have at least noticed it. I know I would have immediately turned to look at what noise I heard in an Apple store (or maybe I'm just hoping to see expensive stuff break every once in a while)
You do know he didn't give it a rock bottom slam, right? It was a slam on the table from about 12 inches. And yes, another employee who was standing right next to him working on his mac did notice it. And as I said in the first post, I asked him for help and he was the one who said I should go try another store perhaps.
Look guys, if you don't believe me, I really can't do much about it. It's like a deja vu for me right now. Trying to talk to a couple Apple "Geniuses" to get my issue sorted out. It's sad that you don't believe me but as I said before, I do understand why you don't.
Anyway, I have had enough responses for my initial question, "Does this happen often?" and that's motivating enough for me to go back and have my issue resolved.
I'm glad though that not every user on this forum is unfriendly like a couple of you because otherwise it would be impossible to get any help from such paranoid users.