For the time being you can manually add/remove the outline style for the focus state of the checkboxes/radio buttons:
CSS:
	<style>
		.rfdRealInput:focus {
			outline: 1px dotted !important;
		}

		.outlineClass {
			outline: 1px dotted !important;
		}
	</style>
JavaScript:
	<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
	<script>
		function pageLoad() {
			$('input[type=checkbox],input[type=radio]').each(function () {
				this.addEventListener('focus', function () { addOutlineClass(this) });
				this.addEventListener('blur', function () { removeOutlineClass(this) });
			});
		}
		function addOutlineClass(checkbox) {
			$(checkbox.nextSibling).addClass("outlineClass");
		}

		function removeOutlineClass(checkbox) {
			$(checkbox.nextSibling).removeClass("outlineClass");
		}
	</script>
ASPX:
		<telerik:RadScriptManager ID="RadScriptManager1" runat="server">
		</telerik:RadScriptManager>
		<telerik:RadFormDecorator ID="RadFormDecorator1" runat="server" DecoratedControls="All" />
		<asp:TextBox ID="Textbox1" runat="server" />
		<asp:RadioButtonList ID="Radiobuttonlist1" runat="server">
			<asp:ListItem Text="text1" />
			<asp:ListItem Text="text2" />
		</asp:RadioButtonList>
		<asp:CheckBoxList ID="Checkboxlist1" runat="server">
			<asp:ListItem Text="text1" />
			<asp:ListItem Text="text2" />
		</asp:CheckBoxList>