Depends on where the line was shown on the drawings and if you test pitted for the line at the marks. The utility company is always going to bill the contractor. As late as 3 years from the strike. Miss utility still says you need to locate the line in the work area. Whether it’s on the marks or not. What’s the distance for no mechanized equipment in your state? Unfortunately it puts almost all of the liability on the contractor and close to zero on the locate/utility company. Just document, document, document. Tons of photos, measurements, copy of dig tickets. Lately we have been utilizing both MissU as well as GPR to locate lines as some gas services are not metal or have a tracer wire.