Robot Safety Grader Was Punishing Robots for Saying "Not"

The open-source QERRA-THRIVE robot safety project fixed a bug where its plan-grader penalized robots that mentioned a hazard only to say they were avoiding it. A plan reading "avoiding driving over the lawn to reach the drop zone" was docked points for a lawn violation, and a robot that said it would not maintain pace but would slow down around personnel was graded as refusing to slow down. Careful robots lost 0.15 to 0.30 points just for being polite, so careless plans that said nothing at all were winning. The fix checks whether a hazard mention is actually describing avoidance before flagging it.