If nothing inside the home was altered you should not be getting a smell. Personally I'm confused as to why the repair person would have left the original line there and ran another one through a new hole. I would have pulled the old line up, ran the new line (in PVC) and used the same hole in the septic tank instead of creating a new one. Did he seal up the hole in the tank from the old line?
Awesome experience with Charlie's Rooter Service! Our outside area drains were overflowing when it rained and about to flood toward the house. I called Charlie's and they had Luis come over within an hour. Luis was super friendly and ready to help when he arrived. He figured out the problem and snaked the street drain and pulled out a huge clump of roots that were clogging it up! But there was still some backup flooding on the side that he was able to isolate to get rid of the mud and debris that were clogging that up. Before leaving, Luis even gave suggestions on how to flush it out periodically to keep things flowing smoothly. Luis is the best and I would definitely use him for future plumbing problems, highly recommended!