Just wanted to let you know that I've encountered a bug with the bottle-breaker-puzzle:
I was able to steal the bottle-breaker from the glass-blower without destroying his unicorns with the cannon first. I've just used the bottle with his bottle-breaker, and although the animation of Guybrush sneaking up to him and getting caught was played, it was followed by the animation of him breaking the bottle.
Then, after destroying the unicorns with the cannon, I could pick up the bottle-breaker again.
I assume this isn't right... is it?