JDS got beaten down and finished by Cain, then beaten up and nearly losing to Stipe (pulled it out due to late momentum and Stipe slowing down) and looked terrible against Overeem (barely throwing any strikes) and getting finished there. Meanwhile Rothwell has been winning against very good opponents, including finishing Overeem and Barnett. You can say Rothwell was behind until he won, but JDS has been behind in all three of this last fights as well (and in only one did he pull out the win, by decision no less not finish like Rothwell has been doing).
JDS could win, he has a great resume, but he and Rothwell are on different trajectories as of late.