I don't think we're dealing with an ordinary mouse.
I don't believe it. He snapped the trap, ate the olive and left the pit just to mock us!
I think you're giving him a little too much credit. Mice don't mock. They don't even have a sense of humor. He's not sitting in his little home in a smoking jacket sipping cognac by the fireplace laughing to himself "I left the pit!" The explanation is simple. The trap snapped itself, the olive flew off and he ate it. But now that he knows we're here, he won't come within a mile of us. As for me, I don't think we'll be seeing any more of that
[sees mouse in cereal bowl]