The Depths problem

In the Depths, May must hit this with their hammer while Cody is on the other side aiming the nail at a circle the platform May hits will swing over to. When that platform lines up with the circle, shoot the nail into the circle to hold the platform in place. Both of you can now cross over it. 

Well, no. May made it across but now the platform is gone back to it's original position & there is no way for Cody to get across. How do I move on from here?