I met Bob in the early '70s when he had only been a JW a couple of years. He was a freelance cartoonist. For several years in the '60s he sold most of his work through his agent, Mario Puzo. Yes, that Mario Puzo. Pulp men's magazines and color DC comics ("Plops") were his staples. He sold single panel cartoons and some of his themes were Dr.s offices, dungeon prisoners, etc and he contributed a lot of content to a mag called "Sex to Sexty". When he became a witness he gave up all the racy, raunchy stuff even though it had been lucrative for him.
He and I became good friends and I would occasionally suggest a 'gag'. Soon he asked for more because he was selling almost all of my stuff. Eventually, I was his main source of material. We would get together a couple of times a week in his little backyard studio and throw out ideas for an afternoon while having some wine, cheese, olives, etc. Great fun. The thing that he let me know right off was that if I came up with a gag that wasn't funny he would immediately say "Not funny" . I got used to the rejections and it helped sharpen me up. Soon, I would say "not funny" back to him if he came up with a dud. He wrote little notes when I came up with a keeper and he would draw them up later and send them to his agent. Every couple of weeks he would pay me 25% of the money he sold them for. (Not a big deal. I averaged $5.00 to $10.00 each).
He taught me that a good cartoon punchline should rely on the illustration to make it work as a cartoon someone could glance at for 5 seconds and get a chuckle out of it. He died at 39 of a heart attack. I'll never forget the few years we had so many laughs.
PS you can google him or "Sex to Sexty" and see some of his work. Be warned, some of his early stuff was pretty raw.