I was up at Dinorwig years ago and found piles of ropes etc strewn around and no one in sight. I eventually found a party in an old building quite some distance away and ascertained that it was their gear.
With such carelessness its hardly surprising that stuff goes missing.
An honest person could easily mistake stuff as being accidentaly left behind.
Years ago at Gunnerside I found a large bag full of photographic equipment, expensive cameras etc. Fortunately there was a name and address in it, in Holland!
I got the postage priced and invited payemnt of this for its return, which it was.
The next year the owner called at my home, they were nice people.