Probably he won't get sick. Dogs are nature's scavengers as well as hunters (in the wild at any rate) They can cope with not-so-fresh meat. But of course it's always best never to let them eat bad meat. I know -trash-bin accident!
You are going to have to put your trash bin inside a cupboard, with a door which locks and is dog-proof.
If anything upsets their tummy they will generally just puke it up, and be better afterwards. The thing to look for would be vomiting more than once, depression, lethargy, etc. Then they need the vet.
But what is very dangerous is if there were any chicken bones??
If so, that could present a real problem, and though the bones might pass through OK, I would call the vet for advice straight away.
How is your dog doing? Let us know, it will help us answer in the future.
My guess is the dog may throw up, that's nature's way of getting rid of bad stuff in the stomach. Then there is diarrhea, the other end of the same story.
My other guess is the dog will not get sick... hope it was just a little, and assume there were not bones stuck in the throat. Chicken bones are about the worse bones for a dog to eat as these bones splinter.
Wishing your dog good health,
Merry Christmas.