I agree, the guy sounds like a first class jerk. Personally, I think you will be fine. Just keep your SA notched up a little and be aware of your surroundings. As the saying goes, "A little paranoia will server you better in times of no friends than a few friends will serve you in a time of no paranoia." If the guy has been in business, he undoubtedly has his bases at least somewhat covered, as in insurance and so forth. I am sure your on his list right now, but he is on yours too. If your legal case has merit, be prepared for a long battle with a lot of emotional ups and downs. If he has more serious problems like with taxes, he is going to have bigger things to worry about than retaliating against you.
In any case, keep positive and focus on the road ahead. That will help maximize your chances for things going your way, including future employment prospects.