Were you going back to the US at the Detriot Windsor tunnel and charged by US CBP?
If it s in the US CBP record it might not be in the CBSA database.
I have relative in Detriot and my wife is from Windsor. What were you thinking buying booze in Windsor with the much higher price? Even street price in Detriot is cheaper than the duty-free shops. If you were trying to take advantage of the sale to 19yrs+ in Ontario vs 21 in Michigan you will be nailed if caught unless there are enough "adults" in the vehicle to match the amount of booze.