I'm guessing he probably got oscillator and oscilloscope confused. Probably quite easy to do if he doesn't really know what they are. Maybe if he's not knowledgeable on this, he though they were the same thing?
Anyway, I often see things where people list an item as something it isn't, or don't bother to spell things properly. Seems quite common. I'm sure this is much more common than it used to be on eBay. In fact, on another forum, I had a good rant a while back about how so many items are so poorly described.