We found Indian Cemetery on June 28th. There were 3 trackables listed in the online inventory and one physical TB in the cache. The physical TB in the cache was not properly dropped in the cache so I had to grab it from another location online. Slowpoke, sadly, is listed in the inventory but not physically in the cache. What does that mean? Your guess is as good as mince... either the cacher who said they actually dropped it back in 2013 didn't physically drop it in the cache OR after they dropped it in the cache a muggle or another cacher decided to not abide by the trackable rules/guidelines and kept/stole your trackable.
As a cache owner and multiple trackables owner, when someone reports that a trackable is not in one of my caches as listed, I mark it missing/move to unknown location. If one of my trackables is reported as not being in a cache as listed, I also mark it missing/move it to an unknown location. You don't have to do this... that is just how I play the game. Sometimes I specifically target a certain cache if it is listed as having trackables and it is always disappointing when I actually find the cache and the trackables aren't really there.