My condolence to your iPad. After hearing your story, I don't think I'll let my 8 yr old boisterous nephew play with it again.....
Hope you find the culprit who dropped your iPad.
Maybe you can get the same friends who played with your iPad to a drinking binge and see who will confess once they are drunk !:D
So I have had actually a similar problem, I got my iPad and immediately installed a full body invisible shield and I baby my iPad and don't let anyone use it. I have never dropped the iPad or been rough with it at all in fact I never take it anywhere unless it is in my padded case. Anyways recently I picked it up and was admiring the beautiful aluminum back and when it shinned in the light I noticed a very small Unevenness in the back... Two slight indents one more noticeable then the other. They are placed and are the size of finger indents however I find it impossible to be able to do that. I am wondering if apple will fix it for free. As i have done nothing wrong yet there aluminum back is very weak on this particular iPad maybe? As of now I have added a hard case. What does everyone think?