Your iPod, your main source of musical inspiration, is not safe. Below is a simple video clip of how a cell phone can disrupt an iPod with wireless transmissions. To extrapolate further, this can be used to damage your downloaded songs and POSSIBLY even the underlying firmware leaving your iPod in a useless state.
Oh come now, saying that because it can do something, it can therefore do anything? It moved the volume. Those wheels are so sensitive that it doesn’t really surprise me. I put a sticker on mine once and the whole thing stopped working. Not to mention it’s a pretty big smartphone sitting about 2mm away. It’s a fun glitch. Settle down. Your iPod is just fine.