Tree Roots in Sewer Line - Scoped when Bought & No Issues Found

[Phil Good]

Hey Guys,

I bought a duplex in Atlanta (first rental property) in early June 2018. Inspection report showed no major issues that the seller didn't fix. Inspector advised inspecting sewer line. I used a plumber recommended by the inspector. The inspection report of the main sewer line reads: 

"Pipe appeared to be operating effectively and there were no immediate emergencies identified. We recommend installation of a clean-out on the exterior of the home. Estimated cost is $1,350.00 which includes removal of cement and patching cement once we are done." 

The report includes two pictures of where the building sewer transitions to PVC and some buildup found in the pipe that was cleaned up. There's also a video of the line starting where the line enters the city supply going back to the house.

I did watch the video. It's a little grainy but it appeared that everything was flowing well, and I didn't see any *obvious* obstructions.

So this past November, one of the tenants was complaining about backup in the toilet and the shower (looked like dirt to me at the time which I thought was strange). I called a plumber out and he just used his plunger to push the discharge in the shower back through the shower drain. No issues until this past week.

This past week (Valentine's day!), same tenant complains about discharge (much worse this time) coming out of the toilet and the shower, and he is adamant that it's poop. I call the plumber out again and we use the 100ft auger to clean the sewer line, and then he scopes it. 

This is his report:

"Customers rental propertytwo units. Basement bathroom branch had a paper stoppage caused byroots collecting paper . Cast-iron pipe is inside house after the drain system turns outside the house it adapts to concrete pipe there is several spots they have roots growing  in at the seams . I ran the large soda machine 100 feet into the citytap clearing stoppage there is still some paper attached to roots on the top inside of the pipe bottom is cleared when pulling backcable there was routes and paper attached to the cable. Spoke with customer and gave him several options one option is to install a two waycleanout outside and Hydro jet the line the second option is to realign the drain after installing a cleanout."

Going back to the video provided when the main sewer line was inspected and knowing what to look for (2nd plumber showed me the feed of the scope last week), I can see tree roots growing out of the line.

Should I try and deal directly with the 1st plumber? Should I go directly to a lawyer? Or am I s*** out of luck?

Thanks,

Phil