Lon Smith Roofing They put an nail into my A/C line and wanted to pay half. Austin, Texas

You are correct. The AC installer ran the line too close to the roof and ANY roofer that did not inspect the attic had a chance to puncture the AC line. 

So after 12 years, I could blame the AC installer, the builder for not catching the error, or the building inspector for not catching a code violation.  Or, I could hold accountable the company that did not take any precaution to avoid an issue that clearly happens on a regular basis.

I'm sure you can get a good crew and were fortunate not to have an issue.  Companies need to stand behind their work and being experts should take some action to avoid problems that they encounter on a regular basis and not try to shift blame to someone else. 

Sounds like the installer of the AC not the roofing companyTo incorrectly install your AC line then your installer is the one that should pay for your AC not the roofing team. Lon Smith has been around a long time and is one of the largest roofers in the business, You dont get that by ripping off the consumer . I have had them perform some roofing repairs for me and the service was outstanding and the ymore then made a effor to provide it to the level they did. Roofing crews dont normally walk through your attic as they assume you had the work done right in the first place . they didnt walk theough my attic first when my roof was done . nor would I suspect the AC installer didnt do their job. Now if you hired a legit AC installer to install your lines this might not have happened or they ( AC installer ) may have stood behind their work. Have you contacted the company that installed your AC lines ? There is a code for that in Austin Tx area to avoid such errors as Houses need reroofed too often here in hail country. I would try with the installer of the AC also as they should have fixed it for free as anyone knows that you will reroof a house sooner or later and a line shouldnt be that close in the first place .It was just a matter of time no mater which company did the roofing