One of the things that I have been thinking about it is how police try to keep secret the locations they clear because they don't want the killer/killers going back to the already cleared area and disposing the body there.
So perhaps they did find some forensic evidence there but they will not be going back either? This is a very highly publicized case and the locations the police is looking are known by the public (NOT ALL).
There is also a possibility there are MORE THAN ONE dumping sites. One for the body one for other evidence. It is definitely strange how it was called off during the day with 1000 volunteers there and with the weather and ground conditions definitely better than previous days. So perhaps the LE were focusing on other leads? Got a good tip for another area???
I don't know if the found Caylee, but logic says the way the search was ended that day and the excuse given is not the most convincing one.