In fact, when I look at the video again, you can see the cop dropping something... a baggie as far as I can tell and then covering it up with a ladder or something. Is it possible that the officers went looking for evidence without having their camera's on (or thinking they had their cameras on), found some evidence and then replaced it in order to find it again with their cameras on so they could document it properly for court purposes? This way they can show where they found the evidence. Not the best or the right method, mind you. They should probably document as they initiate their search so that any evidence found could be documented at the outset. Regardless, this kind of approach is quite common. There is no audio in the clip which is unfortunate since that probably would have confirmed if this was a nefarious planting of evidence or something else.