Workaround is to add the following function override at the end of the page (a sample is attached below)
				Telerik.Web.UI.Editor.Utils.isWindowDestroyed = function (window) {
					var doc;
					try{
						doc = window.document;
					} catch (e) {
						return true;
					}
					if(Telerik.Web.Browser.safari && !doc){
						return true;
					}
					return !doc.defaultView && !doc.parentWindow;
				}