Ask more questions, put EVERYTHING in writing
Initially Jack seemed to be great, we went over the project but in the end many things were not done discussed. They had to be redone. He complained about "this job" that he didn't make any money. Well if he got it right the first time, things might have been different. His son and another guy did a lot of the work, he was not on sight, perhaps this was the problem. He did some electrical work which was unsafe that had to be redone by a qualified electrician, he was working out of realm.