I haven't tested it but it should work in theory. The idea is that given an HTML element belonging to some form (buttonElement) you should get the element of the enclosing window. From this element you can create Kendo UI window object. You can then use Kendo UI API to close it:
var parser = AwareApp.getFormParserFromHtmlElem(buttonElement);
var winElem = $("#" + parser.m_widgetInfo.markupId).parent().closest (".k-window-content");
if (winElem.length > 0)
{
var win = winElem.data ("kendoWindow");
if (win)
win.close ();
}