Missing from cache, perhaps the owner could retrieve it to remove the icon so others are not disappointed. If you do not wish to have it in your inventory you could drop it in this cache. http://www.geocaching.com/seek/cache_details.aspx?guid=349174bc-bb09-4485-955a-ab870db54498 I'm certain there are others like it.
The tracking number can be found by the owner by opening the travelers page, this number is located on the right hand side under tracking options.
This does not affect someone from logging the traveler should it turn-up in their caching bag someday.