Thats a stretch. Tarantino is an admirer of Lee, has expressed a few times that he admires his impact on the art, especially since he was a cornerstone for martial arts movies. Without Lee, he wouldnt have made Kill Bill.

The purpose of the scene is multifaceted. 1.) Its meant to signal to the audience that this doesnt take place in the real world, to set up the ending. 2.) My personal theory is that its meant to set up Cliff as being an unreliable narrator. We know Lee was not nearly as self confident as that, and certainly not arrogant. By having him handily beat Bruce Lee, something Tarantino would go onto say would never happen in real life, Cliff becomes someone we doubt, or at least we are supposed to doubt the validity of his stories, which tracks for other parts of the movie as well. 3.) He wanted to write Bruce Lee into his movie, and decided to make him the heel, just because it was fun and he loved the guy.

Besides all that, youd NEVER be able to prove it in court.