Okay, are you ready for liberal logic? Even though they didn't have a policy that everyone puts their tips in the kitty to be split among the staff (which some restaurants do), they told the girls they had to share the tip with everyone. They didn't want to upset the other employees by someone getting that big of a tip.
Here's where it gets interesting. Some of the people from the dinner party were still hanging around and heard what management was doing. They told the manager they want their tip back. They asked the waitress to go outside, and they gave her the money directly. She was going to split it with the other waitress. It's what the customer wanted, and it was their money; but she lost her job over taking the money. I don't think she cares at this point. She's flush with cash. 😊