It's not done by default, but uploading setWatch(function(){NRF.disconnect()},BTN,{edge:"rising",repeat:true,debounce:50}) should force a disconnect when the button is pressed.
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.
It's not done by default, but uploading
setWatch(function(){NRF.disconnect()},BTN,{edge:"rising",repeat:true,debounce:50})
should force a disconnect when the button is pressed.