Exactly. I did put a call in to the contractor and at the same time I used other tools, such as this website and other sites, to learn more before I spoke with them directly. I wanted to be in a position of speaking intelligently on the situation besides just saying, "the sink gurgles". Before being put into a position of believing just what a contractor might say I thought it wise to learn more and seek opinions from others as to what this might be. Doesn't seem odd to me at all to get multiple opinions. Kind of like going to the doctor - before I would let someone operate on me I would get a second or third opinion.
As regards the code issue, I am located in Dallas, Texas so if anyone knows the code rules there please let me know.