I was not aware that this show was edited with FCPX. It is great to see how popular FCPX has been getting, which is great news for many of us.
This article goes in the details in how they create VR180 in Final Cut Pro X: https://www.fcp.co/final-cut-pro/articles/2276-creating-the-slow-mo-guys-vr180-in-final-cut-pro-x