Most restaurants don't give you the check until you've finished dining. The story at the link verifies the lezzie got the note after serving the dinner. I certainly agree with you, mistreating the waitstaff is really stoopid.
I was basing it on what she said they said when she introduced herself.
From the story “...”Normal introduction, ‘My name is Dayna. I’ll be taking care of you.’ Right away the mom looked at me and said, ‘I thought you were going to say your name was Dan,’” Morales said....”
If it’s true I’d say the couple was rude to boot. But I’d liked to have been at the next table.