I recently sold one of the several Albuquerque homes for sale (my listing) and the buyers were concerned about the sewer line from the home. The age of the home was 50+ years and there was a big tree in the front yard so the inspection was a great idea. The major concern was not only the age of the sewer line but a possible root intrusion that may have occurred in the years past.
The best way to actually see the condition on the line is to hire a professional to scope the line with a fiber-optic camera and digitally video record the inside of the sewer line. Once this is done the inspector will distribute the video to all parties involved and then a decision will be made as to whether the line should be replaced or not. The problem is, who should you hire to scope the line?
If the inspector is not a licensed plumber, someone may end up paying more to have the line scoped again. Often times (this happened twice to me in the past 2 months) the unlicensed inspector will make comments like "could be corrosion" or "could have root infestation" or "may have to be replaced". Comments such as these can raise false red flags and replacing a sewer line can be expensive, like $5k expensive.
Now that this unlicensed inspector has made the comments, the buyer immediately goes on the offensive and wants the line replaced because the guy filming the line has commented, in the video, that he "thinks" the line should be replaced. Now we have to get a second opinion and some plumbing companies charge for second opinions. You may get lucky and have a company accept the first video but they will, more than likely, charge for the time.
So, in my case (both times) this inspector, who was chosen because he was cheaper than the licensed plumber, said that he thought the lines should be replaced. And, in both cases, the line needed to be re-scoped only to have the plumber say that the line was just fine. I think the first, unlicensed inspector should leave his mic off and maybe write his findings down in the written report OR explain to the buyers that he can only give opinions OR become a qualified plumber.