That might be desperation born out of anger and frustration, but she still made a really good bet. Most of them would have likely died fighting the giant snake, and they still could have failed the mission, based on how she called this is a suicide mission earlier. So, she had absolutely nothing to lose. In fact, odds were on her side because not long ago this new species monster had returned the sword to her and then simply let her walk away. A smart move indeed, even if under normal circumstances she wouldn't have been pushed to this point.