Would it better if I make an issue on the github espruino, to ensure this doesn't get buried? Also, if you are super busy and can't get this done, I could attempt a pull request if you'd like, up to you.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
To be fair, buttons can easily bounce more than once - so even that might not stop it (although I'm sure it'd be better).