Just FYI - I lost not one, but TWO bettas to ghost shrimp. One blue male, and one yellow female, both were very aggressive and would eat anything, expecially dead ghost shrimp.
Yeah, you guessed it - they swallowed the ghost shrimp WHOLE! I found them both dead with just the antennea of the shrimp sticking out of their mouths.
I managed to save a third red betta by netting him and pulling the shrimp out by force. It was still alive.
Mind you, I had about five other bettas (males and females) in with ghost shrimp, and they never touched them. I just never knew when it was going to a risk.