It could very well be that the laptop was dropped or otherwise "roughhoused". It wouldn't necessarily happen immediately, though that would be the most likely result. Of course, hard drives sometimes just go bad due to manufacturing defects. No external intervention required.
Just a quick aside though. Work at a small private college doing hardware repairs on desktops and laptops, and I have seen a lot of people who treat their laptops like toys that can be flung about with no real consideration for how delicate they can be. Had a girlfriend once who would just throw her cell phone around like a toddler might throw a toy, and it was her only phone. A lot of people seem to think laptops, and other electronic devices, are far more rugged than they are, and do not treat them very well. It keeps me employed, so I'm not complaining, but it may not have been your friend's kid at all, or the kid may not be solely to blame.
My friend bought his laptop within the last several months-it is under warranty. He installed Windows 7. I am curious as to some of the common reasons why his hard drive crashed. He has a teenage son that has used it on occasion. If the computer was dropped, could this cause a crash and if so, would this happen immediately?