When you go to sell, the same problem will rear it's ugly head.

What kind of RE are you focused on? 

We bought a single family home with a 3 car detached garage on the rear of the property the owner was using for storage. 

Nice work youngster!!

Assuming I win the case (you would think it is a no-brainer but after 4 years, Murphy's law certainly applies here), I will initiate the new eviction process, have the Sheriffs toss his rear on the street, I will fling him the bird, rehab the house, sell for what may be a profit (with the recent increases in value, I should at least break even or come close to it), and then just for my own personal satisfaction, file a small claims suit against him which will follow him for the rest of his natural born miserable life.

The principles of RE are universal as shown.

My daughter lives in the property, with tenant in separate cottage in rear of property. 

The large home is rented by a contractor & even after replacing the asphalt tile roofing it was not covered because now they decided the rear addition roof had too much sag.

Heck if I had the time (and knowledge) to keep all the ducks in a row myself instead of relying on a GC, it would make it that much easier to turn a profit.I'm a scientist - which I guess has some similarities to accountants and bookkeepers :-)  I guess I'm just afraid of making a miscalculation and end up losing my rear end on the first project. 

It also is not knowable except in the rear-view mirror, and a lot of people who think they're going to kill it will miss the boat because they really don't know where the bottom is.