You can't make the assumption that it was an iPod either. My MP3 player is an RCA Lyra, which includes a 1 button voice recorder and a radio tuner. They're cheaper than iPods, and can be purchased in just about as many places.
There are a LOT of lower cost MP3 players on the market that include voice recording capability. This kid may have simply had one in his pocket (my teenage daughter can't be separated from her MP3 player nowadays) when he realized that the situation was getting a bit hairy.
I happen to like iPods but of course you are right, and many of them would not have even required an attachment to record.
D