Guild Wars 2

My guildie and I have beaten Zone 2 already yesterday so we went back again and blazed through it until we got to this point. Last time we were here, feeding the octopus would raise the plate up so that we can get to the next checkpoint by foot. For some reason, the plate stays there and the strings are ripped off from the pulley in an unnatural manner. It might be hard to understand just from this paragraph so I attached a few screenshots.

If this is not a bug, please let us know.

Here is the second screenshot. As you can see, the octopus is on the first floor after giving it a feast of piranhas.

Here is the third screenshot. The plate remains in its initial position, blocking progress.