I guess I would try not to panic. Your husband did the right thing by informing them, but I think he should have accepted the refund because they need to take some sort of responsibility for their food handling. "Being nice" doesn't give them license to have poor food handling techniques.
I think you could have reported it to the Board of Health - if it was just an isolated instance, fine. If it's part of a pattern, then they can inspect the restaurant.
Your "cantaloupe rind" comment in your SWH is not off the wall, actually - I've heard that and I've seen it on "The Doctors" TV show which is not known for excessive panicking. They showed how the salmonella is transferred to the edible part of the fruit just by the slice of a knife. The same has been said of getting wedges of lime or lemon in your drinks at a bar or restaurant. You SHOULD wash the fruits and vegetables even if you don't eat the rind or peel. That means melons, kiwis, even bananas. And I'm not a big "dirt and germs" person but I've also had food poisoning and it's no fun.
I think there's a huge difference between what you experienced and some of the comments of people coming home from the store with produce containing an insect. That DOES happen with unprocessed foods fresh from the farm or vine - we've all opened corn on the cob and found a worm, or found something in a bunch of grapes. Every quantity of dried beans, barley, quinoa, etc. says to pick over it and rinse it, which means looking for bugs as well as pebbles or other debris. The only way you're NOT going to have bugs is if you buy from an over-sprayed pesticide-laden crop - not exactly an appetizing alternative.
But once something's been handled by a professional chef, it should be bug free.