yea maybee your right vlad ,i was a young lad when i heard that saying ,possibly a slight miss interpretation
My understanding was that the knacker was the person whose job it was to dispose of injured or sick livestock. Presumably, the carcasses ended up as glue or fertilizer, not in the food chain. I hope. Anyway, the knacker's yard was the place where farmers took their sick livestock so the knacker could do his job. Other meanings are derived from that. Knacker - Wikipedia
Acadian French is still spoken in Nova Scotia. I suppose that Acadian and "Cajun" French might have drifted apart a little bit in the last 250 years since they were separated geographically. But I suspect they are more similar to each other than they are to either Parisian or Quebec French. My high school French is not bad, but I can't understand a word of Acadian French.