Interesting comment about the Australian dogs eating the stomach contents first. My hound caught a wild rabbit in our yard and ate the entire stomach and lower intestinal track. She was the sickest dog I have ever seen. She threw up 8 huge pile of “barf” and then laid around and hardly moved for 24 hours. She will do it again when she gets the chance I’m sure.
When I read your post and what happened to your dog, two thoughts crossed my mind. The stomach contents were too rich for your dog, and/or the contents were tainted with something. Wild animals get all kinds of things dogs’ systems are not used to dealing with. Hope there were no permanent adverse effects.