My understanding is that the girls intentionally fouled. That is, they stepped out of the circle without throwing, as this typical high school track and field
rulebook describes:
Foul Puts: Not measured
1. The competitor, after stepping into the circle fail to pause before starting the put, or touches the circle, not including the inner face of the stop board or band, if one is used, the ground outside the circle, the top or end of the stop board with any portion of their body before the throw is marked. ...
There's an athletics discussion forum called Let's Run. Mr. M, a former coach and HS and college runner, visits it daily. They talk about everything happening in the world of track and field. Some of the lefties there are
outraged that these five girls "refused" to compete against the boy, accusing them of (and I'm not kidding)
attacking him by stepping out of the circle.