Clearly a hoax. Logically, unless she wears a t-shirt that says “I’m a lesbian!”, unless the people know her, how are they going to know she’s a lesbian?
Was she kissing a girl on the job? Unlikely.
Maybe the lumberjack shirt, the Old Navy pants, the one of five authorized bull dyke lesbian haircuts, the Doc Martens boots, and the spare tire and surly expression tipped them off.
If a couple was at the table, blatantly hitting on the woman while sneering hatefully at the man, and tossing his plate with the wrong order on the table.
Maybe the people at the table were her friends and she told them to not write in a tip because she had this planned all along?
Look for it to be a definite hoax if she all of a sudden she doesn’t want to push this past where it is now. The moment the law is brought into the situation, then these guys fold and confess that they made it up.