So we tested the example code out on IE 11 and also on other browsers. It worked as it should - single, multiple and even all opions were selectable.
The only reason when ZoomCharts would catch events is if would be floating under chart (e.g. using absolute positioning and z-indexes).
In other scenarios there is no interaction between ZoomCharts and rest of the HTML elemens if only some events are binded to HTML elements and our charts. This was not the case in your example.