It's the same way in TX. Nobody can blame you for helping out a friend for what you think is fair. If you were to work the machine for a living, though, my opinion would still stand. I still think you should carry a rider for your machine regardless of where you use it...just to put some protection between you or your customers and a disaster like a gas line or water main.
That is good advice. I would never do any commercial digging, trenching or drilling without being protected. I have been through lawsuits before just doing IT work and a person would have to be insane to work without the protection of general liability. For this guy I quoted him the same as the local post hole company who uses a New Holland. Another bonus is that I am using free fuel salvaged from generator storage tanks that I really need to use before it needs filtering again.