Rain?

Just wondering if there is a written NHRA rule about a racer backing out of the tree due to rain? Was at the ET Finals in Seattle. Overheard one racer talking about it raining, to the point that the track was wet, at the top end of the track. He managed to stop without incident. Sadly another racer did not fare so well. I was about 100' out and I felt a few drips while two racers, in the Pro class, were in the water box. By the time they staged it was raining, not hard but enough that the track was OBVIOUSLY wet. The starter let them go. Guy in the right lane immediately got out of it. Car in the left lane stayed on the throttle a bit longer..and ended up hitting the wall head on. He had enough momentum that the car spun around and hit the wall with the rear as well. Driver was not injured. Car (an A-body) had cosmetic damage. Track allowed the two racers to rerun their pass later that day.
I always thought that the driver was responsible for their own safety. That in a case like this you could simply back out.
Or is this something that each track can have their own "rule"?