In the instance I wrote of, it happened that way I wrote it. Apparently the computer isn’t smart enough to determine which item is illegal, just that there is one.
Perhaps the protocol could be changed so if you have an EBT card, you declare that first and the cashier records your declaration. Then any item that did not qualify for food stamps could be sensed and rejected instantly.
Ok, I assumed that they would run their EBT card first and the remained not covered would be what they owed out of pocket.