Well, I'm not 100% sure (since the article doesn't really tell) but it seems to me that the pit was found in well. Now, I'm doing my phd on cisterns in Greece and trust me when i tell you, there is just about no such thing as a safe context from a well or cistern. Sometimes they are filled by material from old dumps, sometimes they stay empty for centuries when not in use. Sometimes they are left half filled for a few hundred years and then another fill is added on top. It's, from out perspective, completely random. Not to mention the degree to which materials tend to wander in these contexts... A single pit hardly tells us anything here. Unfortunately.