"the property was never transferred to the LLC on the advise of their attorney." Get a letter from the Attorney with those facts, along with a nice big check for all the time you will now need to commit at the worst time of year.

Get a really big retainer and prepare amended LLC returns with no activity for every year that was filed with improper information. This will also require amended returns for all of the LLC members.   

I would be inclined to put on those sneakers, and run as fast as you can if they are unwilling to correct prior year returns for information that was not shared with you.