Actually now that I think about it, it is a bug. It shouldn't just change the candle green, it should replace the bottom with a stick and put the very small top section as a green candle.
Yes. There are plenty of things they could do rather then the way it currently is being implemented. This suggestion here would be the best solution, what I suggested was probably just the simplest way to get around the current "last action during x time period colors the candle" method they use.