Not sure if it should accept text input, which get's geocoded, or not but this can be confusing to users. Perhaps users shouldn't be permitted to interact with the context of the text boxes?
For example on https://www.mapbox.com/mapbox.js/example/v1.0.0/mapbox-directions/ if you immediately enter text into the "A" and "B" text boxes a request is made, but it's incorrectly formatted.