We were once stopped at a roadblock in France for a tour de France pre event leg. It took us a while to work out what was going on - I learnt a lot of new French that day - but we eventually realised we just had to sit it out. For about 3 hours various different people went past. Advertisers, support cars, people cycling!, the wait just went on and on and on. One French guy got so uptight, he actually picked the road barrier up and threw it over a fence, but a group of others then stood in front of his car to stop him moving and collected the barrier and replaced it.
Eventually the Peloton passed in a whoosh of speed, and that was it. We hadn't had any notice they were that close. Nothing more. Barrier raised. Off we went.
Yes, she was stupid and I've not seen the footage of how close she was to actually seeing them coming. But if she had our experience she possibly didn't do it on purpose. She saw the cameras and jumped out having been stood there for ages watching nothing of any interest.
However if it were me I wouldn't have fled and I'd have been in tears trying to help, uselessly.