Wiebes declining to go through and work with Balsamo was the decisive moment. Seeing now that she also lost the sprint for second, maybe she already knew that her legs weren't quite up to the task. Anyway, perfectly played by DSM girls, Georgi even managed to take advantage of some road furniture, which broke the group up bit more.
Largely agree with you on both counts, but Wiebes really couldn't have known she would certainly lose to Balsamo at the time of Georgis attack. So it looked to me that she started playing games when the only real choices were to work or to lose. A tactical error maybe partly caused by doubt in her own strenght.I guess Wiebes also rather wanted to lose to Georgi than Balsamo. That said I think she would have beaten Balsamo if she had been in her wheel instead of opening the sprint herself.