I need advise or help. I have had a couple of occasions where I have detected a gas leak and made a report saying as such. The potential home buyers were with me at the time. So was the sellers agent. All three of us could smell the natural gas in the hallway where the homes gas furnace was. I used my tiff 8800 gas leak detector and marked an area of the gas pipe that I detected a leak from. After a couple of days, the city gas tech. said there was no leak detected and billed my customer $55.00. She in turned called her agent and her agent called me. I returned to the home and once again detected a gas leak (and smell) from the same areas. My question is this. How do I go about handling this situation and not look like a jackass pointing a finger at someone else to blame? Does the tiff 8800 have a defect that I should know about? Thanks for all your help.