After watching the replay from 25km out, I saw no reason to neutralize the GC at the bell, as the course seemed fine. However, I don't think this had any effect on the outcome. The GC riders had almost 10km to get out of the way, which was plenty of time to avoid causing issues.
I think that BlackHand nailed it, there was too much looking around by the field inside of 10km to go, when they still had time to catch them. I saw leadout riders coasting 10 riders back, which means that one guy at the front is hammering and the rest aren't. It has to get wider at the front to get faster. That said, the shot BlackHand posted above shows a reasonable gap between the lead motors and the break. What I saw was nothing like that. They were much closer, clearly giving the break a draft. Commissaire 2 was right behind, and could see this, but took too long to push the motors up. Sometimes this happens on tight downtown circuits, because riders can go faster than the motors in the turns, but this was not the case.
This shot was taken seconds before BlackHand's shot. The motors are way too close. If you think that's perspective, look at the lines on the road, and how many people are on the barriers. They are way too close. I started to notice this on the backside of the course, where the video motor was right in front of them getting the heads-on shot. These things happen in racing. Also notice that Commissaire 2 is behind the break in my shot, and well past the break in BlackHand's. The Commissaire moved themselves along with the unnecessary motors ahead of the race towards the deviation point, as the gap was coming down. They have to do this, where it's wide enough to do so, but that pass of vehicles gives the break a push.