Pretty much in every race a peloton can close much bigger gaps 100 km out, and in fact they did and had it under control. The thirty man break later on was the issue. They all worked together, whereas the peloton were content to let gb chase it down. 4 men having to work against thirty.
Gb were a victim of their own success. The other teams didnt want to help get cav into a sprint situation and held back, but as a result blew their own race