They DID want to catch her alive, after all.

Still, had Nanase been caught in that, she also would have been trapped, and effectively removed from combat.

On a critical fail, she might have also been injured, and she already took a hit from that rock earlier.

Ellen specifies that the minions aren't in danger because I imagine a weighted net plus a lot of dirt falling on people could maybe, JUST MAYBE, be dangerous in real life (GASP!). This danger could be on impact, and/or a consequence of how everything settles after trapping people.

This is a relatively lighthearted chicken rescue adventure, however, so... They're fine.

They need to do some laundry, and get cleaned up a bit, but they're fine.