My biggest question - and it might seem a little ridiculous but hear me out - is was it actually at coordinates that were posted for a geocache? And does it fit the description as well as you can tell (e.g. it's not a micro when the size should be "medium", it's not out in the open when the difficulty is a 5, etc.)? If both of those are yes's, then it would at least be worth checking out. I would try to extract the paper since that would be the log - just make sure you're as careful as possible, especially with very small or not-so-well-maintained logs (I'm very new myself but I've already seen a few that absolutely needed to be handled delicately).
The fact that you describe it as a plastic bag makes me hesitate to say that it's probably the cache, because I can't imagine someone putting out a cache that's a plastic bag, but I could also be misunderstanding your description.
In general, anything that's done in good faith isn't going to get anyone coming after you with pitchforks. You sound like you're trying very hard to do it right and be respectful, so as long as you keep that up I don't think you'll have any major problems. If it is the cache, and the log is in a poor state, notifying the CO is always a good idea, either in your own log or in a message to them if you're not comfortable doing that for whatever reason. Hope this helps!
It's defiantly a small clear plastic Ziploc bag (probably to keep it dry) that contains a folded piece of paper at the exact coordinates, and it is definitely hidden in a location that conforms to other locations where I have found caches.
I/O Error
