Which Momen was Parallel Universe Created?
It's easiest to just say 'button pressed/freeze frame'. But maybe it was right after #2 bomb was unhooked as Colter/Sean was able to call police, call his dad and text Goodwin which he couldn't do previously. And when Colter went back in the final time, he changed Derek's existing 'capture' from surrendering from his van to being found handcuffed on the train. This could be one of the reasons Dr. Rutledge had for avoiding sending Colter back in because he could goof up accidentally.