The "out" for exclusive use is that if your Mom used that same piece of property too, it wasn't the lawyer's exclusive use and that should defeat a claim of adverse possession.Here's a good article: https://www.nolo.com/legal-enc...My first instinct would be to break the chain of continuous use by setting up a "no trespassing" sign and taking a date stamped photo. 

I have date/gps time stamped photos from before move in and after.

If for some inexplicable reason the lawyer decides to file a lawsuit, (highly unlikely from what you've described here) you will receive a "Complaint" (a serious looking document with all kinds of court stamps on it).

I remember them now and their flannel shirts. 

Have the neighbors keep a diary, supply you with written complaint(s) and set up video in common areas--make sure there are time/date stamps on the recordings. 

Nobody ever lost their shirts because they thought the market might fail. 

Of course the pictures are date/time stamped.

shorts and golf shirt in 8C weather  LOL..  

Use some date stamp method to show this is happening often.

People are so well off as “poor” they sell their food stamps, section 8 while spending 300$ a month on hair and nails.