Some additional context for those who don't follow professional cycling: the Dutch women's team was incredibly strong coming into this road race. All 4 riders on their team are stars in their own right, and the only reason there wasn't a clear favorite for the race overall is that people weren't sure which Dutch rider would win.

So you have a complicated group dynamic, where the majority of the peloton has no interest in pulling the group to catch the break, since they would just get beat by one or more of the Dutch riders, and the Dutch riders didn't seem to have a clear plan on how to control the race and who would sacrifice their chances and work on the front for the rest of the team.

As others have said, there were no radios allowed for riders in the race, so all information about the breakaway came from the race director's car trailing the peloton. This was a well known fact about the race coming in, and it's the same way that the annual World Championship race is run. It's normal for riders to drop back to the team car to get information about the break, and the lead moto for a group of cyclists will occasionally show time gaps on a whiteboard.

At least one of the Dutch riders claimed to have known about the lone rider off the front [1], but somehow that information didn't make it to the rest of the team. It seems that most of the peloton didn't know (or didn't care) how many riders were up the road, and the Dutch team failed to communicate amongst themselves and establish a plan.

All that leads to Kiesenhofer's solo move working out. All credit to her for an extremely strong ride.

[1]https://netherlandsnewslive.com/miscommunication-and-underes...