I’m not sure how there could be human error on the part of Rosscarberrys connections. It’s too much of a coincidence to think they put the wrong weight in to start with and then weighed in light as well. The mathematical chance of these two errors occurring would be too big. It has to be an issue with the scales or clerk.
As for the mobile ads I can well believe this. Amazons Alexas are programmed to make suggestions to their owners based on conversations they have been having.