For what it's worth, it came to me from a friend I went to high school with who was told this by a friend of his who works for the Blazers that we both went to HS with. I don't think either the guy I know, or the guy* it originated from, would make it up.
And it wasn't just ONE person that LA didn't tip - he didn't tip anyone. He took his money and went home.
*The guy the info came from has been mentioned on the forum.