How would you handle a situation where your co-worker was being rude to customers?

"I worked as a server in a busy pub a few years ago. While serving one of my tables, I overheard another servers' table complaining about how terrible their service had been so far. Obviously, my co-worker wasn't feeling a connection with that table and was feeling overwhelmed by the volume of work. I approached my co-worker and offered to take the table off her hands as she seemed very busy. She happily agreed. I approached the table positively, apologetic for their needs not being met, and assured them that I was going to take care of them. I paid close attention to their table for the rest of the evening. This was a win-win solution because the customers left happy, and my co-worker felt I was helping, rather than judging her behavior."